The SSL VPN feature or WebVPN provides support in the Cisco IOS software for remote user access to enterprise networks from anywhere on the Internet. Remote access is provided through a Secure Socket Layer (SSL)-enabled SSL VPN gateway. The SSL VPN gateway allows remote users to establish a secure VPN tunnel using a web browser. This feature provides a comprehensive solution that allows easy access to a broad range of web resources and web-enabled applications using native HTTP over SSL (HTTPS) browser support. SSL VPN delivers three modes of SSL VPN access: clientless, thin-client, and full-tunnel client support.
This document is primarily for system administrators. If you are a remote user, see the document"SSL VPN Remote User Guide".
Note
The Cisco AnyConnect VPN Client is introduced in Cisco IOS Release 12.4(15)T. This feature is the next-generation SSL VPN Client. If you are using Cisco software earlier than Cisco IOS Release 12.4(15)T, you should be using the SSL VPN Client and use the GUI for the SSL VPN Client when you are web browsing. However, if you are using Cisco Release 12.4(15)T or a later release, you should be using the Cisco AnyConnect VPN Client and use the GUI for Cisco AnyConnect VPN Client when you are web browsing.
Note
Security threats, as well as the cryptographic technologies to help protect against them, are constantly changing. For more information about the latest Cisco cryptographic recommendations, see the
Next Generation Encryption (NGE) white paper.
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see
Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for SSL VPN
To securely access resources on a private network behind an SSL VPN gateway, the remote user of an SSL VPN service must have the following:
An account (login name and password)
An SSL-enabled browser (for example, Internet Explorer, Netscape, Mozilla, or Firefox)
Operating system support
"Thin client" support used for TCP port-forwarding applications requires administrative privileges on the computer of the remote user.
"Tunnel mode" for Cisco SSL VPN requires administrative privileges for initial installation of the full tunnel client.
The remote user must have local administrative privileges to use thin client or full tunnel client features.
The SSL VPN gateway and context configuration must be completed before a remote user can access resources on a private network behind an SSL VPN. For more information, see the
How to Configure SSL VPN Services on a Router section.
ACL Support--The time range should have already been configured.
Single SignOn Netegrity Cookie Support--A Cisco plug-in must be installed on a Netegrity SiteMinder server.
Licensing--In Cisco IOS Release 15.0(1)M, the SSL VPN gateway is a seat-counted licensing feature on Cisco 880, Cisco 890, Cisco 1900, Cisco 2900, and Cisco 3900 platforms. A valid licence is required for a successful SSL VPN session.
SSL VPN-supported browser--The following browsers have been verified for SSL VPN. Other browsers might not fully support SSL VPN features.
Note
Later versions of the following software are also supported.
Firefox 2.0 (Windows and Linux)
Internet Explorer 6.0 or 7.0
Linux (Redhat RHEL 3.0 +, FEDORA 5, or FEDORA 6)
Macintosh OS X 10.4.6
Microsoft Windows 2000, Windows XP, or Windows Vista
URLs referred by the Macromedia Flash player cannot be modified for secure retrieval by the SSL VPN gateway.
Cisco Secure Desktop (CSD) 3.1 and later versions are not supported.
Cisco AnyConnect VPN Client
The Cisco AnyConnect VPN Client is not supported on Windows Mobile when the client connects to a Cisco IOS headend router (supported in Cisco IOS Release 15.0(1)M and later releases). The Cisco AnyConnect VPN Client does not support the following:
Client-side authentication (supported in Cisco IOS Release 15.0(1)M and later releases)
Compression support
IPsec
IPv6 VPN access
Language translation (localization)
Sequencing
Standalone Mode (supported in Cisco IOS Release 12.4(20)T and later releases)
Thin Client Control List Support
Although there is no limitation on the maximum number of filtering rules that can be applied for each access control list (ACL) entry, keeping the number below 50 should have no impact on router performance.
HTTP Proxy
The HTTP Proxy feature works only with Microsoft Internet Explorer.
The HTTP Proxy feature will not work if the browser proxy setup cannot be modified because of any security policies that have been placed on the client workstation.
Features Not Supported on the Cisco IOS SSL VPN
The following features are not supported on the Cisco IOS SSL VPN:
Application Profile Customization Framework (APCF): an XML-based rule set for clientless SSL VPN
Java and ActiveX Client Server Plugins
On Board Built-in Single Sign On
Smart Tunnels
SharePoint Support
Portal Page Customization
Using Smartcard for Authentication (supported in Cisco IOS Release 15.0(1)M and later releases)
Support for External Statistics Reporting and Monitoring Tools
Lightweight Directory Access Protocol (LDAP) Support
Dynamic Access Policies (DAP)
Cisco Unified Communications Manager (Cisco UCM) 8.0.1 VPN-enabled 7900 series IP phones
The following features introduced in the AnyConnect 2.5.217 release:
AnyConnect Profile Editor
Captive Portal Hotspot Detection
Captive Portal Remediation
Client Firewall with Local Printer and Tethered Device Support
Connect Failure Policy
Optimal Gateway Selection
Post Log-in Always-on VPN
Quarantine
Although you can connect to a Cisco IOS headend using AnyConnect 2.5, the features introduced in AnyConnect 2.5 will not be supported. However, features introduced in AnyConnect 2.4 and earlier releases are supported when you are using AnyConnect 2.5 with a Cisco IOS headend.
Note
AnyConnect 3.0 is not supported when you are connecting to a Cisco IOS headend.
Cisco IOS SSL VPN provides SSL VPN remote-access connectivity from almost any Internet-enabled location using only a web browser that natively supports SSL encryption. This feature allows your company to extend access to its secure enterprise network to any authorized user by providing remote-access connectivity to corporate resources from any Internet-enabled location.
Cisco IOS SSL VPN can also support access from noncorporate-owned machines, including home computers, Internet kiosks, and wireless hot spots. These locations are difficult places to deploy and manage VPN client software and the remote configuration required to support IPsec VPN connections.
The figure below shows how a mobile worker (the lawyer at the courthouse) can access protected resources from the main office and branch offices. Site-to-site IPsec connectivity between the main and remote sites is unaltered. The mobile worker needs only Internet access and supported software (web browser and operating system) to securely access the corporate network.
Figure 1
Secure SSL VPN Access Model
SSL VPN delivers the following three modes of SSL VPN access:
Clientless--Clientless mode provides secure access to private web resources and will provide access to web content. This mode is useful for accessing most content that you would expect to access in a web browser, such as Internet access, databases, and online tools that employ a web interface.
Thin client (port-forwarding Java applet)--Thin-client mode extends the capability of the cryptographic functions of the web browser to enable remote access to TCP-based applications such as Post Office Protocol version 3 (POP3), Simple Mail Transfer Protocol (SMTP), Internet Message Access protocol (IMAP), Telnet, and Secure Shell (SSH).
Tunnel mode--Full tunnel client mode offers extensive application support through its dynamically downloaded Cisco AnyConnect VPN Client (next-generation SSL VPN Client) for SSL VPN. Full tunnel client mode delivers a lightweight, centrally configured and easy-to-support SSL VPN tunneling client that provides network layer access to virtually any application.
SSL VPN application accessibility is somewhat constrained relative to IPsec VPNs; however, SSL-based VPNs provide access to a growing set of common software applications, including web page access, web-enabled services such as file access, e-mail, and TCP-based applications (by way of a downloadable thin-client applet). SSL-based VPN requires slight changes to user workflow because some applications are presented through a web browser interface, not through their native GUI. The advantage for SSL VPN comes from accessibility from almost any Internet-connected system without needing to install additional desktop software.
Licensing
Starting in Cisco IOS Release 15.0(1)M, the SSL VPN gateway is a seat-counted licensing feature on the Cisco 880, Cisco 890, Cisco 1900, Cisco 2900, and Cisco 3900 platforms. A license count is associated with each license, and the count indicates the instances of the feature available for use in the system. In the case of SSL VPN, a seat refers to the maximum number of sessions allowed at a time.
Permanent licenses--No usage period is associated with these licenses. All permanent licenses are node locked and validated during installation and usage.
Evaluation licenses--These are metered licenses that are valid for a limited period. The usage period of a license is based on a system clock. The evaluation licenses are built into the image and are not node locked. The evaluation licenses are used only when there are no permanent, extension or grace period licenses available for a feature. An end-user license agreement (EULA) has to be accepted before using an evaluation license.
Extension licenses--Extension licenses are node-locked metered licenses. These licenses are installed using the management interfaces on the device. A EULA has to be accepted as part of installation.
Grace-rehost licenses--Grace period licenses are node locked metered licenses. These licenses are installed on the device as part of the rehost operation. A EULA has to be accepted as a part of the rehost operation.
For all the license types, except the evaluation license, a EULA has to be accepted during the license installation. This means that all the license types except the evaluation license are activated after installation. In the case of an evaluation license, a EULA is presented during an SSL VPN gateway configuration or an SSL VPN context configuration.
An SSL VPN session corresponds to a successful login to the SSL VPN service. An SSL VPN session is created when a valid license is installed and the user credentials are successfully validated. On a successful user validation, a request is made to the licensing module to get a seat. An SSL VPN session is created only when the request is successful. If a valid license is not installed, the SSL VPN gateway configuration and SSL VPN context configurations are successful, but the user cannot login successfully. When multiple gateways and contexts are configured, the total number of sessions are equal to the total sessions allowed by the license.
The same user can create multiple sessions and for each session a seat count is reserved. The seat reservation does not happen in the following cases:
Multiple TCP connections such as web server content, Outlook Web Access (OWA) and Common Intermediate Format (CIF) file shares.
Port forward session initiation.
Full tunnel session creation from a browser session.
Full tunnel session is up and a crypto rekey is done.
When the total active sessions are equal to the maximum license count of the current active license, no more new sessions are allowed.
The reserved seat count or session is released when
a user logs out.
a Dead Peer Detection (DPD) failure happens.
a session timeout occurs.
an idle timeout occurs.
a session is cleared administratively using the
clear webvpn session command.
disconnected from the tunnel.
context is removed even when there are active sessions.
You can use the
show webvpn license command to display the available count and the current usage. To display the current license type and time period left in case of a nonpermanent license, use the
show license command. To get information related to license operations, events, and errors, use the
debug webvpn license command.
New Cisco IOS SSL VPN licenses that are generated are cumulative. Therefore the old licenses become inactive when a new license is applied. For example, when you are upgrading your license from 10 counts to 20 counts (an increase of 10 counts on the current 10 counts), Cisco provides a single 20 count license. The old license for 10 counts is not required when a permanent license for a higher count is available. However, the old license will exist in an inactive state as there is no reliable method to clear the old license.
In Cisco IOS Release 15.1(4)M1 and later releases, a Crypto Export Restrictions Manager (CERM) license is reserved only after the user logs in. If you have an Integrated Services Router Generation 2 (ISR G2) router with a CERM license, you must upgrade to Cisco IOS Release 15.1(4)M1 or later releases. Before Cisco IOS Release 15.1(4)M1, a CERM license is reserved for every SSL or Transport Layer Security (TLS) session.
End-user login and authentication is performed by the web browser to the secure gateway using an HTTP request. This process creates a session that is referenced by a cookie. After authentication, the remote user is shown a portal page that allows access to the SSL VPN networks. All requests sent by the browser include the authentication cookie. The portal page provides all the resources available on the internal networks. For example, the portal page could provide a link to allow the remote user to download and install a thin-client Java applet (for TCP port forwarding) or a tunneling client.
The figure below shows an overview of the remote access modes.
Figure 2
Modes of Remote Access Overview
The following table summarizes the level of SSL VPN support that is provided by each access mode.
Table 1
Access Mode Summary
A-- Clientless Mode
B--Thin-Client Mode
C--Tunnel Mode
Browser-based (clientless)
Microsoft Windows or Linux
Web-enabled applications, file sharing, Outlook Web Access
Gateway performs address or protocol conversion and content parsing and rewriting
Tunnel client loaded through Java or ActiveX (approximately 500 kB)
Application agnostic--supports all IP-based applications
Scalable
Local administrative permissions required for installation
Clientless Mode
In clientless mode, the remote user accesses the internal or corporate network using the web browser on the client machine. The PC of the remote user must run the Windows 2000, Windows XP, or Linux operating systems.
The following applications are supported in clientless mode:
Web browsing (using HTTP and HTTPS)--provides a URL box and a list of web server links in the portal page that allows the remote user to browse the web.
File sharing (using common Internet file system [CIFS])--provides a list of file server links in the portal page that allows the remote user to do the following operations:
Browse a network (listing of domains)
Browse a domain (listing of servers)
Browse a server (listing of shares)
List the files in a share
Create a new file
Create a directory
Rename a directory
Update a file
Download a file
Remove a file
Rename a file
Note
Linux requires that the Samba application is installed before CIFS file shares can be remotely accessed.
Web-based e-mail, such as Microsoft Outlook Web Access (OWA) 2003 (using HTTP and HTTPS) with Web Distributed Authoring and Versioning (WebDAV) extensions--provides a link that allows the remote user to connect to the exchange server and read web-based e-mail.
Thin-Client Mode
Thin-client mode, also called TCP port forwarding, assumes that the client application uses TCP to connect to a well-known server and port. In thin-client mode, the remote user downloads a Java applet by clicking the link provided on the portal page, or the Java applet is downloaded automatically (see the
Options for Configuring HTTP Proxy and the Portal Page and Options for Configuring HTTP Proxy and the Portal Page section). The Java applet acts as a TCP proxy on the client machine for the services that you configure on the gateway.
The applications that are supported in thin-client mode are mainly e-mail-based (SMTP, POP3, and Internet Map Access Protocol version 4 [IMAP4]) applications.
Note
The TCP port-forwarding proxy works only with the Sun Microsystems Java Runtime Environment (JRE) version 1.4 or later versions. A Java applet is loaded through the browser that verifies the JRE version. The Java applet will refuse to run if a compatible JRE version is not detected.
The Java applet initiates an HTTP request from the remote user client to the SSL VPN gateway. The name and port number of the internal e-mail server is included in the HTTP request (POST or CONNECT). The SSL VPN gateway creates a TCP connection to that internal e-mail server and port.
The Java applet starts a new SSL connection for every client connection.
You should observe the following restrictions when using thin-client mode:
The remote user must allow the Java applet to download and install.
You cannot use thin-client mode for applications such as FTP, where the ports are negotiated dynamically. You can use TCP port forwarding only with static ports.
Note
There is a known compatibility issue with the encryption type and Java. If the Java port-forwarding applet does not download properly and the configuration line
ssl encryption 3des-sha1 aes-sha1 is present, you should remove the line from the WebVPN gateway subconfiguration.
Options for Configuring HTTP Proxy and the Portal Page
Effective with Cisco IOS Release 12.4(11)T, administrators have more options for configuring the HTTP proxy and the portal page. If HTTP proxy is enabled, the Java applet acts as the proxy for the browser of the user, thereby connecting the client workstation with the gateway. The home page of the user (as defined by the user group) is opened automatically or, if configured by the administrator, the user is directed to a new website.
HTTP proxy supports both HTTP and HTTPS.
Benefits of Configuring HTTP Proxy
HTTP supports all client-side web technologies (including HTML, Cascading Style Sheets [CSS], JavaScript, VBScript, ActiveX, Java, and flash), HTTP Digest authentication, and client certificate authentication. Remote users can use their own bookmarks, and there is no limit on cookies. Because there is no mangling involved and the client can cache the objects, performance is much improved over previous options for configuring the HTTP proxy and portal page.
Illustrations of Port Forwarding with and Without an HTTP Proxy Configuration
The figure below illustrates TCP port forwarding without HTTP proxy configured.
Figure 3
TCP Port Forwarding Without HTTP Proxy Configured
In the figure above, the following steps occur:
User downloads the proxy applet.
Applet updates the registry to add HTTP as a Remote Procedure Call (RPC) transport.
Applet examines the registry to determine the exchange (and local catalog) server and create server entries that refer to those servers.
Applet opens local port 80 and listens for connections.
User starts Outlook, and Outlook connects to 10.0.0.254:80.
Applet opens a connection to the secure gateway and delivers the requests from Outlook.
Secure gateway examines the requests to determine the endpoint exchange server.
Data flows from Outlook, through the applet and the secure gateway, to the exchange server.
User terminates Outlook.
User closes the applet. Before closing, the applet undoes configuration Steps 3 and 4.
The figure below illustrates TCP port forwarding when HTTP proxy is configured.
Figure 4
HTTP Proxy
In the figure above, the following steps occur:
Proxy applet is downloaded automatically.
Applet saves the original proxy configuration of the browser.
Applet updates the proxy configuration of the browser to be the local loopback address with an available local port (by default, port 8080).
Applet opens the available local port and listens for connections.
Applet, if so configured, opens the home page of the user, or the user browses to a new website.
Applet accepts and looks at the HTTP or HTTPS request to determine the destination web server.
Applet opens a connection to the secure gateway and delivers the requests from the browser.
Secure gateway examines the requests to determine the endpoint web server.
Data flows from the browser, through the applet and the secure gateway, to the web server.
User closes applet. Before closing, the applet undoes configuration Steps 2 and 3.
Note
HTTP proxy can also be enabled on an authentication, authorization, and accounting (AAA) server. See the table SSL VPN RADIUS Attribute-Value Pairs in the
Configuring RADIUS Attribute Support for SSL VPN section (port-forward-http-proxy and port-forward-http-proxy-url attributes).
Tunnel Mode
In a typical clientless remote access scenario, remote users establish an SSL tunnel to move data to and from the internal networks at the application layer (for example, web and e-mail). In tunnel mode, remote users use an SSL tunnel to move data at the network (IP) layer. Therefore, tunnel mode supports most IP-based applications. Tunnel mode supports many popular corporate applications (for example, Microsoft Outlook, Microsoft Exchange, Lotus Notes E-mail, and Telnet).
The tunnel connection is determined by the group policy configuration. The Cisco AnyConnect VPN Client is downloaded and installed on the remote user PC, and the tunnel connection is established when the remote user logs into the SSL VPN gateway.
By default, the Cisco AnyConnect VPN Client is removed from the client PC after the connection is closed. However, you have the option to keep the Cisco AnyConnect VPN Client installed on the client PC.
Effective with Cisco IOS Release 12.4(20)T, administrators can configure automatic authentication and authorization for users. Users provide their usernames and passwords via the gateway page URL and do not have to reenter their usernames and passwords from the login page. Authorization is enhanced to support more generic authorization, including local authorization. In previous releases, only RADIUS authorization was supported.
This feature enables SSL VPN to authenticate clients based on the client's AAA username and password and also supports WebVPN gateway authentication of clients using AAA certificates.
SSL VPN Client-Side Certificate-Based Authentication feature includes the following features:
Certificate-Only Authentication and Authorization Mode
Certificate-only authorization requires the user to provide a AAA authentication certificate as part of the WebVPN request, but does not require the username and password for authorization. The user requests WebVPN access with the AAA authentication certificate from the WebVPN gateway. The WebVPN gateway validates the identity of the client using the AAA authentication certificate presented to it. The WebVPN extracts the username from the AAA authentication certificate presented to it and uses it as the username in the AAA request. AAA authentication and AAA authorization are then completed with a hard-coded password. To configure certificate-only authorization use the authenticationcertificate command.
Two-Factor Authentication and Authorization Mode
Two-factor authorization requires the user to request WebVPN access and present a AAA authentication certificate. The AAA authentication certificate is validated and the client's identity is verified. The WebVPN gateway then presents the login page to the user. The user enters their username and password and WebVPN sends AAA authentication and AAA authorization requests to the AAA server. The AAA authentication list and the AAA authorization lists configured on the server are then used for authentication and authorization. To configure two-factor authentication and authorization mode use the authenticationcertificateaaa command.
Note
If the username-prefill command is configured, the username textbox on the login page will be disabled. The user will be asked only for their password on the login page.
Identification of WebVPN Context at Runtime Using Certificate Map Match Rules
Certificate map match rules are used by SSL VPN to identify the WebVPN context at runtime. The WebVPN context is required for AAA authentication and authorization mode and trustpoint configuration. When the user does not provide the WebVPN context, the identification of the WebVPN context at runtime is possible using certificate map matching by matching the certificate presented by the client with the certificate map match rules. To configure certificate map matching in WebVPN use the match-certificate command.
Support for AnyConnect Client to Implement Certificate Matching Based on Client Profile Attributes
Cisco AnyConnect client has certificate match functionality allowing it to select a suitable certificate while initiating tunnel connection with SSL VPN. In the case of standalone mode, the certificate selection is made based on the certificate match. When selecting a certificate, Cisco AnyConnect client can select the appropriate certificate based on the AnyConnect client profile attributes. This requires SSL VPN to support AnyConnect client profiles. The profile file is imported after modification by the administrator using the svcprofile command. To create an AnyConnect client profile use the template that appears after installing Cisco AnyConnect in this location: \Documents and Settings\All Users\Application Data\Cisco\ CiscoAnyConnectVPNClient\Profile\AnyConnectProfile.tmpl.
The following are the certificate match types available with Cisco AnyConnect client:
Certificate Key Usage Matching
Certificate key usage matching offers a set of constraints based on the broad types of operations that can be performed with a given certificate.
Extended Certificate Key Usage Matching
This matching allows an administrator to limit the certificates that can be used by the client based on the Extended Key Usage fields.
Certificate Distinguished Name Mapping
This certificate matching capability allows an administrator to limit the certificates that can be used by the client to those matching the specified criteria and criteria match conditions. This includes the ability to specify that a certificate must or must not have a specified string and also if wild carding for the string should be allowed.
AnyConnect Client Support
Effective with Cisco IOS Release 12.4(20)T, AnyConnect Client support is added for several client-side platforms, such as Microsoft Windows, Apple-Mac, and Linux. The ability to install AnyConnect in a standalone mode is also added. In addition, the Release 12.4(20)T allows you to install multiple AnyConnect VPN client packages to a gateway. For information on configuring multiple packages, see the section "Configuring the SSL VPN Gateway to Distribute CSD and Cisco AnyConnect VPN Client Package Files."
Application ACL Support
Effective with Cisco IOS Release 12.4(11)T, the Application ACL Support feature provides administrators with the flexibility to fine-tune access control at the application layer level, for example, on the basis of a URL.
Effective with Cisco IOS Release 12.4(9)T, administrators have the option of automatically downloading the port-forwarding Java applet. The Automatic Applet Download feature must be configured on a group policy basis.
Note
Users still have to allow the Java applet to be downloaded. The dialog box appears, asking for permission.
The Backend HTTP Proxy feature, added in Cisco IOS Release 12.4(20)T, allows administrators to route user requests through a backend HTTP proxy, providing more flexibility and control than routing requests through internal web servers. This feature adds the following new AAA attributes:
Effective with Cisco IOS Release 12.4(15)T, front-door virtual routing and forwarding (FVRF) support, coupled with the already supported internal virtual routing and forwarding (IVRF), provides for increased security. The feature allows the SSL VPN gateway to be fully integrated into a Multiprotocol Label Switching (MPLS) or non-MPLS network (wherever the VRFs are deployed). The virtual gateway can be placed into a VRF that is separate from the Internet to avoid internal MPLS and IP network exposure. This placement reduces the vulnerability of the router by separating the Internet routes or the global routing table. Clients can now reach the gateway by way of the FVRF, which can be separate from the global VRF. The backend, or IVRF, functionality remains the same.
This FVRF feature provides for overlapping IP addresses.
The figure below is a scenario in which FVRF has been applied.
Effective with Cisco IOS Release 12.4(20)T, Full-Tunnel Cisco Express Forwarding support is added for better throughput performance than in earlier releases. This feature is enabled by default. To turn off full-tunnel Cisco Express Forwarding support, use the
no webvpn cef command.
Note
To take full advantage of Cisco Express Forwarding support, the hardware crypto engine is required.
Network Address Translation (NAT) configuration is sometimes used to forward TCP port 443 traffic destined to the WAN interface of a router through an internal webserver.
There are two methods of implementing Cisco IOS SSL VPN on a preexisting NAT configuration. The Cisco-recommended method is to use the WebVPN gateway IP address as the secondary address on the WAN interface. This method helps improve the WebVPN throughput performance. The following is a sample configuration of the recommended method on Cisco IOS SSL VPN:
interface GigabitEthernet 0/0
ip address 10.1.1.1 255.255.255.0
ip address 10.1.1.2 255.255.255.0 secondary !
webvpn gateway ssl_vpn
ip address 10.1.1.2 port 443
In the second method the WebVPN gateway uses a private IP address configured on a loopback interface and performs a NAT operation to convert the private IP address to a publically routable address. The following configuration is not supported on Cisco IOS SSL VPN because this configuration causes packets to become process-switched instead of being Cisco Express Forwarding-switched:
interface Loopback 10
ip address 192.0.2.1 255.255.255.0
!
interface GigabitEthernet 0/0
description WAN interface
ip address 10.1.1.1 255.0.0.0
!
ip nat inside source static 192.0.2.1 10.1.1.2 !
webvpn gateway ssl_vpn
ip address 192.0.2.1 port 443
GUI Enhancements
In Cisco IOS Release 12.4(15)T, ergonomic improvements are made to the GUI of the Cisco IOS SSL VPN gateway. The improved customization of the user interface provides for greater flexibility and the ability to tailor portal pages for individualized views. Enhancements are made to the following web screens:
The figure below is an example of a typical login screen.
Figure 6
Typical Login Screen
Banner
The banner is a small popup box that appears after the user is logged in and before the portal page appears.
The message in the popup box is configured using the
banner command.
Figure 7
Banner
Customization of a Login Page
Login screens can be customized by an administrator. The following figure shows the fields that can be customized.
For information about setting various elements of the login page, see the document
Cisco IOS Security Command Reference, Release 12.4T, for the
color,
logo,
login-message,
login-photo,
secondary-color,
text-color,
title,
title-color, and
text-color commands.
Figure 8
Login Page with Callouts of the Fields That Can Be Customized
Portal Page
The portal page (see the figure below) is the main page for the SSL VPN functionality. You can customize this page to contain the following:
Custom logo (the default is the Cisco bridge logo)
Custom title (the default is "WebVPN Services")
Custom banner (the default is an empty string)
Custom colors (the default is a combination of white and greens)
List of web server links (can be customized)
Note
The Bookmark links are listed under the Personal folder, and the server links are listed under Network File in the figure below.
URL entry box (may be present or can be hidden using the
hide-url-bar command)
Thin Client link (may or may not be present)
Note
The Application Access box allows you to download and install the Tunnel Connection and Thin Client Application.
Links for Help, Home (that is, the portal page), and Logout
Items that you have not configured are not displayed on the portal page.
Note
E-mail access is supported by thin-client mode, which is downloaded using the Thin Client link.
The figure below is an example of a typical portal page.
Figure 9
Typical Portal Page
Note
Time to redirect to the home page is displayed on the WebVPN portal page if you have configured the home page redirect time using the
webvpn-homepage command. See the
Cisco IOS Security Command Reference for information about the
webvpn-homepage command. You can click the "Click here to stop homepage redirection" link to stop redirection.
Customization of a Portal Page
Portal pages can be customized by an administrator. The following figure shows various fields, including the fields that can be customized by an administrator. The fields that can be customized by an administrator are as follows:
Title
Logo
Secondary color
Administrator-defined bookmarks
Color
Figure 10
Portal Page with Callouts of Various Fields, Including Those That Can Be Customized
The table below provides information about various fields on the portal page. For information about setting elements such as color or titles, see command information in the
Cisco IOS Security Command Reference, Release 12.4T, for the
color,
functions,
hide-url-bar,
logo,
port-forward,title,
title-color,
secondary-color,
secondary-text-color, and
url-list commands.
Table 2
Information About Fields on the Portal Page
Field
Description
User-level bookmark add icon
If a user clicks it, a dialog box is added so that a new bookmark can be added to the Personal folder.
Network File location bar
A user can enter the file server here. Both of the
functionsfile-access and
functionsfile-entry commands must be configured for the input box to appear.
Header
Shares the same color value as the title.
Last login
Time stamp of the last login.
Browse network
Allows a user to browse the file network. The
functionsfile-access and
functionsfile-browse commands must be configured for the icon to appear.
Tunnel Connection
A user can choose when to start the tunnel connection by configuring thefunctionssvc-enabled command.
Port forwarding
Downloads the applet and starts port forwarding.
User-level bookmark edit icon
Allows a user to edit or delete an existing bookmark.
User-level bookmarks
A user can add a bookmark by using the plus icon
on the bookmark panel or toolbar. See the document
SSL VPN Remote User Guide for information about the toolbar. A new window is opened when the link is clicked.
Administrator-defined bookmarks
Administrator-defined URL lists cannot be edited by the user.
URL address bar
A new window is opened when a user clicks Go.
Internationalization
The Internationalization feature provides multilanguage support for messages initiated by the headend for SSL VPN clients, such as Cisco Secure Desktop (CSD) and SSL VPN Client (SVC). With the Internationalization feature, administrators can import their own attribute files in an XML format so that other languages can be imported using an editor that supports multilanguages.
The figure below shows a portal page in English. Users can select any language you have imported for certain SSL VPN web pages (login message, title page, and URL lists).
Figure 11
Portal Page in English
The figure below shows that an administrator has imported files in Japanese. A user has selected Japanese as the language for certain SSL VPN web pages (login message, title, and URL lists).
A user that tries to log in to a Web VPN context when the maximum user limit has been reached receives a "Max-user limit reached" message.
Netegrity Cookie-Based Single SignOn Support
The Netegrity SiteMinder product provides a Single SignOn feature that allows a user to log in a single time for various web applications. The benefit of this feature is that users are prompted to log in only once. This feature is accomplished by setting a cookie in the browser of a user when the user initially logs in.
Effective with Cisco IOS Release 12.4(11)T, Netegrity cookie-based SSO is integrated with SSL VPN. It allows administrators to configure an SSO server that sets a SiteMinder cookie in the browser of a user when the user initially logs in. This cookie is validated by a SiteMinder agent on subsequent user requests to resources that are protected by a SiteMinder realm. The agent decrypts the cookie and verifies whether the user has already been authenticated.
For more information about configuring RADIUS accounting, see the
Configuring RADIUS module in the
Cisco IOS Security Configuration Guide: Securing User Services.
Stateless High Availability with Hot Standby Router Protocol
Hot Standby Router Protocol (HSRP) provides high network availability by routing IP traffic from hosts on Ethernet networks without having to rely on the availability of any single router. HSRP is particularly useful for hosts that do not support a router discovery protocol, such as ICMP Router Discovery Protocol (IRDP), and that do not have the functionality to switch to a new router when their selected router reloads or loses power. Without this functionality, a router that loses its default gateway because of a router failure is unable to communicate with the network.
HSRP is configurable on LAN interfaces using standby CLI. It is possible to use the standby IP address from an interface as the local IPsec identity, or local tunnel endpoint.
You can use the standby IP address as the SSL VPN gateway address to apply failover to VPN routers by using HSRP. Remote SSLVPN users connect to the local VPN gateway using the standby address that belongs to the active device in the HSRP group. In the event of failover, the standby device takes over ownership of the standby IP address and begins to service remote VPN users.
Using the Stateless High Availability with Hot Standby Router Protocol feature, the remote user has to be aware of only the HSRP standby address instead of a list of gateway addresses.
The figure below shows the enhanced HSRP functionality topology. Traffic is serviced by the active Router P, the active device in the standby group. In the event of failover, traffic is diverted to Router S, the original standby device. Router S assumes the role of the new active router and takes ownership of the standby IP address.
In the case of a failover, HSRP does not facilitate SSL VPN state information transfer between VPN gateways. Without this state transfer, existing SSL VPN sessions with the remote users will be deleted, requiring users to reauthenticate and establish SSL VPN sessions with the new active gateway.
TCP Port Forwarding and Thin Client
Note
The TCP Port Forwarding and Thin Client feature requires the Java Runtime Environment (JRE) version 1.4 or later releases to properly support SSL connections.
Note
Because this feature requires installing JRE and configuring the local clients, and because doing so requires administrator permissions on the local system, it is unlikely that remote users will be able to use applications when they connect from public remote systems.
When the remote user clicks the Start button of the Thin Client Application (under "Application Access), a new window is displayed. This window initiates the downloading of a port-forwarding applet. Another window is then displayed. This window asks the remote user to verify the certificate with which this applet is signed. When the remote user accepts the certificate, the applet starts running, and port-forwarding entries are displayed (see the figure below ). The number of active connections and bytes that are sent and received is also listed on this window.
Note
When remote users launch Thin Client, their system may display a dialog box regarding digital certificates, and this dialog box may appear behind other browser windows. If the remote user connection hangs, tell the remote user to minimize the browser windows to check for this dialog box.
You should have configured IP addresses, Domain Name System (DNS) names, and port numbers for the e-mail servers. The remote user can then launch the e-mail client, which is configured to contact the e-mail servers and send and receive e-mails. POP3, IMAP, and SMTP protocols are supported.
The window attempts to close automatically if the remote user is logged out using JavaScript. If the session terminated and a new port forwarding connection is established, the applet displays an error message.
Figure 14
TCP Port Forwarding Page
Caution
Users should always close the Thin Client window when finished using applications by clicking the close icon. Failure to quit the window properly can cause Thin Client or the applications to be disabled. See the section "Application Access--Recovering from Hosts File Errors" in the document
SSL VPN Remote User Guide.
The table below lists remote system requirements for Thin Client.
Table 3
SSL VPN Remote System Thin-Client Requirements
Remote User System Requirements
Specifications or Use Suggestions
Client applications installed.
-
Cookies enabled on browser.
-
Administrator privileges.
You must be the local administrator on your PC.
Sun Microsystems JRE version 1.4 or later installed.
SSL VPN automatically checks for JRE whenever the remote user starts Thin Client. If it is necessary to install JRE, a popup window displays directing remote users to a site where it is available.
Client applications configured, if necessary.
Note
The Microsoft Outlook client does not require this configuration step.
To configure the client application, use the locally mapped IP address and port number of the server. To find this information, do the following:
Start SSL VPN on the remote system and click the Thin-Client link on the SSL VPN home page. The Thin-Client window is displayed.
In the Name column, find the name of the server that you want to use, and then identify its corresponding client IP address and port number (in the Local column).
Use this IP address and port number to configure the client application. The configuration steps vary for each client application.
Windows XP SP2 patch.
If you are running Windows XP SP2, you must install a patch from Microsoft that is available at the following address:
The URL Obfuscation feature provides administrators with the ability to obfuscate, or mask, sensitive portions of an enterprise URL, such as IP addresses, hostnames, or part numbers. For example, if URL masking is configured for a user, the URL in the address bar could have the port and hostname portion obfuscated, as in this example:
Effective with Cisco IOS Release 12.4(20)T, the URL Rewrite Splitter feature allows administrators to mangle selective URLs. Mangling is a CPU-intensive and time-consuming process, so mangling only selective URLs can result in a savings of memory and time.
Effective with Cisco IOS Release 12.4(15)T, users can bookmark URLs while connected through an SSL VPN tunnel. Users can access the bookmarked URLs by clicking the URLs.
User-level bookmarking is turned by default. There is no way to turn it off. To set the storage location, administrators can use the
user-profile location command. If the
user-profile location command is not configured, the location flash:/webvpn/{context name}/ is used.
Virtual Templates
A virtual template enables SSL VPN to interoperate with IP features such as Network Address Translation (NAT), firewall, and policy-based routing.
The Cisco IOS SSL VPN accepts license strings from Cisco IP Phones. Cisco IOS VPN concentrators support the VPN license type linksys-phone in order to support the Galactica VPN client on 79x
2 and 79x
5 phones.
In the case of a transformer platform, response to the license message (linksys-phone) will succeed if the license requirements are met. However, an Integrated Services Routers (ISR) router must always respond with a success message so that the Galactica VPN client can attempt to establish a VPN connection.
SSLVPN DVTI Support
The SSLVPN DVTI Support feature adds Dynamic Virtual Tunnel Interface (DVTI) support to the Secure Socket Layer Virtual Private Network (SSL VPN) and hence enables seamless interoperability with IP features such as Firewall, Network Address Translation (NAT), Access Control Lists (ACLs), and Virtual Routing and Forwarding (VRF). This feature also provides DVTI support, which allows IP feature configuration on a per-tunnel basis.
SSL VPN provides three modes to access a VPN: clientless, thin client, and full tunnel. The full tunnel mode uses an internal virtual interface to route the traffic to and from the SSL VPN tunnel. Before the SSL VPN DVTI Support feature was introduced, the virtual interface was created during the SSL VPN virtual interface configuration and users were not allowed to apply IP features to the SSL VPN traffic.
The SSLVPN DVTI Support feature uses a virtual template infrastructure to provide DVTI support for SSL VPN. IP features are configured in a virtual template that is associated with the SSL VPN or WebVPN context. The IP features configured in the virtual template are used to create a virtual access interface that is internally used to tunnel SSL VPN traffic. Virtual templates in a WebVPN context are applied in two ways: per-context and per-tunnel.
Note
You can configure any IP feature with SSL VPN. However, in the Cisco IOS Release 15.1(1)T, interoperability has been tested only with the firewall, NAT, ACL, policy-based routing (PBR), and VRF IP features.
The SSL VPN DVTI Support feature contains the following:
You must have the IP features configured in a virtual template. See the
Configuring a Virtual Template section for information on configuring a virtual template.
SSL VPN must be able to fetch configurations from the AAA server.
The SSL VPN gateway and context configurations must be enabled and operational.
If VRF is needed, configure it before creating the virtual template.
Restrictions for SSLVPN DVTI Support
In order for a virtual template to work with SSL VPN, the ipunnumbered command must be configured on the virtual template.
Virtual Template Infrastructure
A generic interface template service is required with features such as stackability, Virtual Private Dialup Network (VPDN), Multilink PPP (MLP), and virtual profiles. Virtual template interface service delivers a generic interface template service. The virtual template interface, command buffer, and virtual access interface functions enables you to populate a virtual-access interface using a pre-defined configuration that is stored in a virtual template interface and security servers such as TACACS+ and RADIUS.
For example, in stackability, a virtual template interface is assigned to a stack group. Whenever a stack member needs a virtual interface, the virtual template interface service is called by a member to obtain a virtual access interface cloned with the same configuration as the configuration of the assigned virtual template interface.
In a virtual profile, the per-user configuration can be stored in a security server. That is, when the user dials in, the desired configuration can be cloned into the virtual access interface associated with the user. The virtual template service provides an application programming interface (API) for a virtual profile to clone a buffer of commands to a virtual access interface. The virtual profile does the actual interaction with the security server.
Note
If you do not configure a virtual template, then the default virtual template (VT0) will be used for cloning the virtual access interface.
SSL VPN Phase-4 Features
The SSL VPN Phase-4 Features feature provides the following enhancements to the Cisco IOS Secure Sockets Layer Virtual Private Network (SSL VPN):
ACL support for split tunneling
IP mask for IP pool address assignment
Undoing the renaming of AnyConnect or SSL VPN Client (SVC) Full Tunnel Cisco package during installation on a Cisco IOS router
Adding per-user SSL VPN session statistics
"Start before logon" option for the Cisco IOS SSL VPN headend
The SSL VPN Phase-4 features contains the following:
You must use a valid K9 image to configure the SSL VPN Phase-4 Features.
Full Tunnel Package
When you install the AnyConnect or SVC full tunnel package using the
webvpn install svc command on the Cisco IOS headend, the package name gets renamed to svc_pkg_<number>. This renaming omits package information and Base Station Ethernet (BSE) operating system information, and thus makes you difficult to remove or uninstall the package. This functionality was modified in Cisco IOS Release 15.1(1)T to retain the name during installation of the package.
The limit on the filename size on the Cisco IOS file system (IFS) is 120 bytes. Unless the package name is greater than this limit, the package name does not change. If the filename exceeds this limit, then the installation fails. The following error message is displayed on the router console:
Error: Package name exceeds 120 characters
SSL VPN per-User Statistics
Per-user statistics functionality provides an option to filter the cumulative statistics on a per-user basis for the Cisco IOS SSL VPN sessions. Use the
showwebvpnsessionuser command to enable this functionality. This command is applicable only for user session statistics and tunnel statistics. See
Cisco Cisco IOS Security Command Reference for more information on the
showwebvpnsession command.
DTLS Support for IOS SSL VPN
The DTLS Support for IOS SSL VPN feature enables DTLS as a transport protocol for the traffic tunneled through SSL VPN.
An AnyConnect client with a Transport Layer Security (TLS) tunnel can face problems for real-time traffic and the traffic that is not sensitive to data loss, such as VoIP. This happens because of the delay introduced by the TCP channel (AnyConnect client uses TLS over TCP channel). Also, when the TCP sessions are channeled over the TLS tunnel we have TCP in TCP. Here both the TCPs try to control the flow and achieve in-sequence reliable delivery. This causes slow down of the application and also increases the network bandwidth utilization. DTLS solves this problem by hosting TLS over UDP after making the necessary changes to TLS.
The DTLS Support for IOS SSL VPN feature is enabled by default on the Cisco IOS SSL VPN. You can use the
no svc dtls command in the WebVPN group policy configuration mode to disable the DTLS support on the SSL VPN.
The Cisco AnyConnect VPN Client software package is pushed from the SSL VPN gateway to remote clients when support is needed. The remote user (PC or device) must have either the Java Runtime Environment for Windows (version 1.4 later), or the browser must support or be configured to permit Active X controls. In either scenario, the remote user must have local administrative privileges.
Address Pool
The address pool is first defined with the iplocalpool command in global configuration mode. The standard configuration assumes that the IP addresses in the pool are reachable from a directly connected network.
Address Pools for Nondirectly Connected Networks
If you need to configure an address pool for IP addresses from a network that is not directly connected, perform the following steps:
Create a local loopback interface and configure it with an IP address and subnet mask from the address pool.
Configure the address pool with the iplocalpool command. The range of addresses must fall under the subnet mask configured in Step 1.
Set up the route. If you are using the Routing Information Protocol (RIP), configure the routerripcommand and then the network command, as usual, to specify a list of networks for the RIP process. If you are using the Open Shortest Path First (OSPF) protocol, configure the ipospfnetworkpoint-to-point command in the loopback interface. As a third choice (instead of using the RIP or OSPF protocol), you can set up static routes to the network.
Configure thesvcaddress-pool command with the name configured in Step 2.
Manual Entry to the IP Forwarding Table
If the SSL VPN software client is unable to update the IP forwarding table on the PC of the remote user, the following error message will be displayed in the router console or syslog:
Error : SSL VPN client was unable to Modify the IP forwarding table ......
This error can occur if the remote client does not have a default route. You can work around this error by performing the following steps:
Open a command prompt (DOS shell) on the remote client.
Enter the
route print command.
If a default route is not displayed in the output, enter the
route command followed by the
add and
mask keywords. Include the default gateway IP address at the end of the route statement. See the following example:
C:\>route ADD 0.0.0.0 MASK 0.0.0.0 10.1.1.1
Other SSL VPN Features
The following table lists the requirements for various SSL VPN features.
Table 4
SSL VPN Remote User System Requirements
Task
Remote User System Requirements
Additional Information
Web Browsing
Usernames and passwords for protected websites
Users should log out on SSL VPN sessions when they are finished.
The look and feel of web browsing with SSL VPN might be different from what users are accustomed to. For example, when they are using SSL VPN, the following should be noted:
The SSL VPN title bar appears above each web page.
Websites can be accessed as follows:
Entering the URL in the Enter Web Address field on the SSL VPN home page
Clicking a preconfigured website link on the SSL VPN home page
Clicking a link on a webpage accessed by one of the previous two methods
Also, depending on how a particular account was configured, the following might have occurred:
Some websites are blocked.
Only the websites that appear as links on the SSL VPN home page are available.
Network Browsing and File Management
File permissions configured for shared remote access
Server name and passwords are necessary for protected file servers
Domain, workgroup, and server names where folders and files reside
Only shared folders and files are accessible through SSL VPN.
A user might not be familiar with how to locate files through the network of an organization.
Note
You should not interrupt the Copy File to Server operation or navigate to a different window while the copying is in progress. Interrupting this operation can cause an incomplete file to be saved on the server.
If you use an IMAP client and lose the e-mail server connection or you are unable to make a new connection, you should close the IMAP application and restart SSL VPN.
To use e-mail, users must start Thin Client from the SSL VPN home page. The e-mail client is then available for use.
Microsoft Outlook Express versions 5.5 and 6.0 have been tested.
SSL VPN should support other SMTPS, POP3S, or IMAP4S e-mail programs, such as Netscape Mail, Lotus Notes, and Eudora, but they have not been verified.
Using e-mail: Web Access
Web-based e-mail product installed
Supported products are as follows:
OWA 5.5, 2000, and 2003
Netscape, Mozilla, and Internet Explorer are supported with OWA 5.5 and 2000.
Internet Explorer 6.0 or a later version is required with OWA 2003. Netscape and Mozilla are supported with OWA 2003.
Lotus Notes
Operating system support:
Note
Later versions of the following browsers are also supported.
Microsoft Windows 2000, Windows XP, or Windows Vista
Macintosh OS X 10.4.6
Linux (Redhat RHEL 3.0 +, FEDORA 5, or FEDORA 6)
SSL VPN-supported browser:
The following browsers have been verified for SSL VPN. Other browsers might not fully support SSL VPN features.
Note
Later versions of the following software are also supported.
Internet Explorer 6.0 or 7.0
Firefox 2.0 (Windows and Linux)
Safari 2.0.3
Other web-based e-mail products should also work, but they have not been verified.
Using the Cisco Tunnel Connection
--
To retrieve Tunnel Connection log messages using the Windows Event Viewer, go to Program Files > Administrative Tools > Event Viewer in Windows.
Using Secure Desktop Manager
A Secure Desktop Manager-supported browser
On Microsoft Windows:
Internet Explorer version 6.0 or 7.0
Netscape version 7.2
On Linux:
Netscape version 7.2
Using Cache Cleaner or Secure Desktop
A Cisco Secure Desktop-supported browser
Any browser supported for Secure Desktop Manager.
Platform Support
For information about platform support for the SSL VPN feature, see the data sheet
Cisco IOS SSL VPN
("Feature Availability" section).
The SSL VPN gateway acts as a proxy for connections to protected resources. Protected resources are accessed through an SSL-encrypted connection between the gateway and a web-enabled browser on a remote device, such as a personal computer. Entering the
webvpn gateway command places the router in SSL VPN gateway configuration mode. The following configuration are accomplished in this task:
The gateway is configured with an IP address.
A port number is configured to carry HTTPS traffic (443 is default).
A hostname is configured for the gateway.
Crypto encryption and trust points are configured.
The gateway is configured to redirect HTTP traffic (port 80) over HTTPS.
The gateway is enabled.
Note
Security threats, as well as the cryptographic technologies to help protect against them, are constantly changing. For more information about the latest Cisco cryptographic recommendations, see the
Next Generation Encryption (NGE) white paper.
The SSL VPN provides remote-access connectivity from almost any Internet-enabled location using only a web browser and its native SSL encryption. The
ssl encryption command is configured to restrict the encryption algorithms that SSL uses in Cisco IOS software.
Note
There is a known compatibility issue with the encryption type and Java. If the Java port-forwarding applet does not download properly and the configuration line
ssl encryption 3des-sha1 aes-sha1 is present, you should remove the line from the WebVPN gateway subconfiguration.
The configuration of the
ssl trustpoint command is required only if you need to configure a specific certification authority (CA) certificate. A self-signed certificate is automatically generated when an SSL VPN gateway is put in service.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpngatewayname
4.hostnamename
5.ipaddressnumber [portnumber] [standbyname]
6.http-redirect [portnumber]
7.sslencryption [aes-sha1] [3des-sha1] [rc4-md5]
8.ssltrustpointname
9.inservice
10.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Device> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Device# configure terminal
Enters global configuration mode.
Step 3
webvpngatewayname
Example:
Device(config)# webvpn gateway GW_1
Enters WebVPN gateway configuration mode to configure an SSL VPN gateway.
Only one gateway is configured in an SSL VPN-enabled network.
Step 4
hostnamename
Example:
Device(config-webvpn-gateway)# hostname VPN_1
(Optional) Configures the hostname for an SSL VPN gateway.
Step 5
ipaddressnumber [portnumber] [standbyname]
Example:
Device(config-webvpn-gateway)# ip address 10.1.1.1
(Optional) Configures a proxy IP address on an SSL VPN gateway.
Step 6
http-redirect [portnumber]
Example:
Device(config-webvpn-gateway)# http-redirect
(Optional) Configures HTTP traffic to be carried over HTTPS.
When this command is enabled, the SSL VPN gateway listens on port 80 and redirects HTTP traffic over port 443 or the port number specified with the
port keyword.
SSL VPN context and policy group configurations must be configured before an SSL VPN gateway can be operationally deployed. Proceed to the section "Configuring an SSL VPN Context" to see information on SSL VPN context configuration.
Configuring a Generic SSL VPN Gateway
To configure a generic SSL VPN gateway, perform the following steps in privileged EXEC mode.
Note
The advantage of this configuration over the one in the configuration task in the
Configuring an SSL VPN Gateway is that basic commands and context can be configured quickly using just the
webvpn enable command.
SUMMARY STEPS
1.enable
2.webvpnenablegateway-addrip-address
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
webvpnenablegateway-addrip-address
Example:
Router# webvpn enable gateway-addr 10.1.1.1
Configures a generic SSL VPN gateway.
Configuring an SSL VPN Context
The SSL VPN context defines the virtual configuration of the SSL VPN. Entering the
webvpn context command places the router in SSL VPN configuration mode. The following configurations are accomplished in this task:
A gateway and domain is associated.
The AAA authentication method is specified.
A group policy is associated.
The remote user portal (web page) is customized.
A limit on the number users sessions is configured.
The context is enabled.
The
ssl authenticate verify all command is enabled by default when a context configuration is created. The context cannot be removed from the router configuration while an SSL VPN gateway is in an enabled state (in service).
A virtual hostname is specified when multiple virtual hosts are mapped to the same IP address on the SSL VPN gateway (similar to the operation of a canonical domain name). The virtual hostname differentiates host requests on the gateway. The host header in the HTTP message is modified to direct traffic to the virtual host. The virtual hostname is configured with the
gateway command in WebVPN context configuration mode.
Before You Begin
The SSL VPN gateway configuration has been completed.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpncontextname
4.aaaauthentication {domainname |
listname}
5.policygroupname
6.exit
7.default-group-policyname
8.exit
9.gatewayname [domainname |
virtual-hostname]
10.inservice
11.login-message [message-string]
12.logo [filefilename |
none]
13.max-usersnumber
14.secondary-colorcolor
15.secondary-text-color {black |
white}
16.title [title-string]
17.title-colorcolor
18.svcplatform{lin |
mac |
win}
seqsequence-number
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpncontextname
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Tip
The context can be optionally named using the domain or virtual hostname. This is recommended as a best practice. It simplifies the management of multiple context configurations.
(Optional) Associates an SSL VPN gateway with an SSL VPN context.
Step 10
inservice
Example:
Router(config-webvpn-gateway)# inservice
(Optional) Enables an SSL VPN context configuration.
The context is put "in service" by entering this command. However, the context is not operational until it is associated with an enabled SSL VPN gateway.
Step 11
login-message [message-string]
Example:
Router(config-webvpn-context)# login-message "Please enter your login credentials"
(Optional) Configures a message for the user login text box displayed on the login page.
Step 12
logo [filefilename |
none]
Example:
Router(config-webvpn-context)# logo file flash:/mylogo.gif
(Optional) Configures a custom logo to be displayed on the login and portal pages of an SSL VPN.
The source image file for the logo is a gif, jpg, or png file that is up to 255 characters in length (filename) and up to 100 KB in size.
The file is referenced from a local file system, such as flash memory. An error message will be displayed if the file is not referenced from a local file system.
No logo will be displayed if the image file is removed from the local file system.
Step 13
max-usersnumber
Example:
Router(config-webvpn-context)# max-users 500
(Optional) Limits the number of connections to an SSL VPN that will be permitted.
(Optional) Configures the color of the secondary title bars on the login and portal pages of an SSL VPN.
The value for the
color argument is entered as a comma-separated red, green, blue (RGB) value, an HTML color value (beginning with a pound sign [#]), or the name of the color that is recognized in HTML (no spaces between words or characters). The value is limited to 32 characters. The value is parsed to ensure that it matches one of the following formats (using Perl regex notation):
\#/x{6}
\d{1,3},\d{1,3},\d{1,3} (and each number is from 1 to 255)
\w+
The default color is purple.
Step 15
secondary-text-color {black |
white}
Example:
Router(config-webvpn-context)# secondary-text-color white
(Optional) Configures the color of the text on the secondary bars of an SSL VPN.
The color of the text on the secondary bars must be aligned with the color of the text on the title bar.
The default color is black.
Step 16
title [title-string]
Example:
Router(config-webvpn-context)# title "Secure Access: Unauthorized users prohibited"
(Optional) Configures the HTML title string that is shown in the browser title and on the title bar of an SSL VPN.
The optional form of the
title command is entered to configure a custom text string. If this command is issued without entering a text string, a title will not be displayed in the browser window. If the
no form of this command is used, the default title string "WebVPN Service" is displayed.
(Optional) Specifies the color of the title bars on the login and portal pages of an SSL VPN.
The value for the
color argument is entered as a comma-separated red, green, blue (RGB) value, an HTML color value (beginning with a pound sign [#]), or the name of the color that is recognized in HTML (no spaces between words or characters). The value is limited to 32 characters. The value is parsed to ensure that it matches one of the following formats (using Perl regex notation):
\#/x{6}
\d{1,3},\d{1,3},\d{1,3} (and each number is from 1 to 255)
\w+
The default color is purple.
Step 18
svcplatform{lin |
mac |
win}
seqsequence-number
Example:
Router(config-webvpn-context)# svc platform lin seq 1
(Optional) Configures the platform of an AnyConnect version per context.
If the
svc platform command is not used, AnyConnect is configured in standalone mode.
The
seq keyword assigns a priority number to an AnyConnect client in the same platform. The range of sequence-number argument is from 1 to 10.
An SSL VPN policy group configuration must be defined before an SSL VPN gateway can be operationally deployed. Proceed to the Configuring an SSL VPN Policy Group to see information on SSL VPN policy group configuration.
Configuring an SSL VPN Policy Group
The policy group is a container that defines the presentation of the portal and the permissions for resources that are configured for a group of remote users. Entering the policygroup command places the router in WebVPN group policy configuration mode. After it is configured, the group policy is attached to the SSL VPN context configuration by configuring the default-group-policy command. The following tasks are accomplished in this configuration:
The presentation of the SSL VPN portal page is configured.
A NetBIOS server list is referenced.
A port-forwarding list is referenced.
The idle and session timers are configured.
A URL list is referenced.
Outlook Web Access (OWA) 2003 is supported by the SSL VPN gateway upon completion of this task. The Outlook Exchange Server must be reachable by the SSL VPN gateway via TCP/IP.
A URL list can be configured under the SSL VPN context configuration and then separately for each individual policy group configuration. Individual URL list configurations must have unique names.
At the completion of this task, the SSL VPN gateway and context configurations are operational and enabled (in service), and the policy group has been defined. The SSL VPN gateway is operational for clientless remote access (HTTPS only). Proceed to the Configuring Local AAA Authentication for SSL VPN User Sessions to see information about configuring AAA for remote-user connections.
Configuring Local AAA Authentication for SSL VPN User Sessions
The steps in this task show how to configure a local AAA database for remote-user authentication. AAA is configured in global configuration mode. In this task, the aaaauthentication command is not configured under the SSL VPN context configuration. Omitting this command from the SSL VPN context configuration causes the SSL VPN gateway to use global authentication parameters by default.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
The database that is configured for remote-user authentication on the SSL VPN gateway can be a local database, as shown in this task, or the database can be accessed through any RADIUS or TACACS+ AAA server.
It is recommended that you use a separate AAA server, such as a Cisco ACS. A separate AAA server provides a more robust security solution. It allows you to configure unique passwords for each remote user and accounting and logging for remote-user sessions. Proceed to the Configuring AAA for SSL VPN Users Using a Secure Access Control Server to see more information.
Configuring AAA for SSL VPN Users Using a Secure Access Control Server
The steps in this task show how to configure AAA using a separate RADIUS or TACACS+ server. AAA is configured in global configuration mode. The authentication list or method is referenced in the SSL VPN context configuration with the aaaauthentication command. The steps in this task configure AAA using a RADIUS server.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
A RADIUS or TACACS+ AAA server is operational and reachable from the SSL VPN gateway.
Configuring RADIUS Accounting for SSL VPN User Sessions
Before You Begin
Before configuring RADIUS accounting for SSL VPN user sessions, you should first have configured AAA-related commands (in global configuration mode) and have set the accounting list.
SUMMARY STEPS
1.enable
2.configureterminal
3.aaanew-model
4.webvpncontextcontext-name
5.aaaaccountinglistaaa-list
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
aaanew-model
Example:
Router(config)# aaa new-model
Enables the AAA access control model.
Step 4
webvpncontextcontext-name
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 5
aaaaccountinglistaaa-list
Example:
Router(config-webvpn-context)# aaa accounting list list1
Enables AAA accounting when you are using RADIUS for SSL VPN sessions.
Monitoring and Maintaining RADIUS Accounting for an SSL VPN Session
To monitor and maintain your RADIUS accounting configuration, perform the following steps (the debug commands can be used together or individually).
SUMMARY STEPS
1.enable
2.debugwebvpnaaa
3.debugaaaaccounting
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
debugwebvpnaaa
Example:
Router# debug webvpn aaa
Enables SSL VPN session monitoring for AAA.
Step 3
debugaaaaccounting
Example:
Router# debug aaa accounting
Displays information on accountable events as they occur.
Configuring RADIUS Attribute Support for SSL VPN
This section lists RADIUS attribute-value (AV) pair information introduced to support SSL VPN. For information on using RADIUS AV pairs with Cisco IOS software, see the "Configuring RADIUS" chapter in the
RADIUS Configuration Guide.
The following table shows information about SSL VPN RADIUS attribute-value pairs. All SSL VPN attributes (except for the standard IETF RADIUS attributes) start with
webvpn: as follows:
Configuring a URL List for Clientless Remote Access
The steps in this configuration task show how to configure a URL list. The URL list, as the name implies, is a list of HTTP URLs that are displayed on the portal page after a successful login. The URL list is configured in WebVPN context configuration and WebVPN group policy configuration modes.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpncontextname
4.url-listname
5.headingtext-string
6.url-textnameurl-valueurl
7.exit
8.policygroupname
9.url-listname
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpncontextname
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 4
url-listname
Example:
Router(config-webvpn-context)# url-list ACCESS
Enters WebVPN URL list configuration mode to configure the list of URLs to which a user has access on the portal page of an SSL VPN.
Step 5
headingtext-string
Example:
Router(config-webvpn-url)# heading "Quick Links"
Configures the heading that is displayed above URLs listed on the portal page of an SSL VPN.
The heading for the URL list is entered as a text string. The heading must be entered inside of quotation marks if it contains spaces.
Configuring Microsoft File Shares for Clientless Remote Access
In clientless remote access mode, files and directories created on Microsoft Windows servers can be accessed by the remote client through the HTTPS-enabled browser. When clientless remote access is enabled, a list of file server and directory links is displayed on the portal page after login. The administrator can customize permissions on the SSL VPN gateway to provide limited read-only access for a single file or full-write access and network browsing capabilities. The following access capabilities can be configured:
Network browse (listing of domains)
Domain browse (listing of servers)
Server browse (listing of shares)
Listing files in a share
Downloading files
Modifying files
Creating new directories
Creating new files
Deleting files
Common Internet File System Support--CIFS is the protocol that provides access to Microsoft file shares and support for common operations that allow shared files to be accessed or modified.
NetBIOS Name Service Resolution--Windows Internet Name Service (WINS) uses NetBIOS name resolution to map and establish connections between Microsoft servers. A single server must be identified by its IP address in this configuration. Up to three servers can be added to the configuration. If multiple servers are added, one server should be configured as the master browser.
Samba Support--Microsoft file shares can be accessed through the browser on a Linux system that is configured to run Samba.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
A Microsoft file server is operational and reachable from the SSL VPN gateway over TCP/IP.
Note
File shares configured on Windows 2008 is not supported. Only file shares configured on Microsoft Windows 2000, Windows 2003, Windows XP, and Red Hat Linux servers are supported.
Entering the
file-access keyword enables network file share access. File servers in the server list are listed on the SSL VPN portal page when this keyword is enabled.
Entering the
file-browse keyword enables browse permissions for server and file shares. The file-access function must be enabled in order to also use this function.
Entering the
file-entry keyword enables "modify" permissions for files in the shares listed on the SSL VPN portal page.
Configuring Citrix Application Support for Clientless Remote Access
Clientless Citrix support allows the remote user to run Citrix-enabled applications through the SSL VPN as if the application were locally installed (similar to traditional thin-client computing). Citrix applications run on a MetaFrame XP server (or server farm). The SSL VPN gateway provides access to the remote user. The applications run in real time over the SSL VPN. This task shows how to enable Citrix support for policy group remote users.
The Independent Computing Architecture (ICA) client carries keystrokes and mouse clicks from the remote user to the MetaFrame XP server. ICA traffic is carried over TCP port number 1494. This port is opened when a Citrix application is accessed. If multiple application are accessed, the traffic is carried over a single TCP session.
Before You Begin
A Citrix MetaFrame XP server is operational and reachable from the SSL VPN gateway over TCP/IP.
SSL VPN gateway and context configurations are enabled and operational.
Support for standard applications that use well-known port numbers, such as e-mail and Telnet, can be configured using the port forwarding feature. See the Configuring Application Port Forwarding for more information.
Configuring Application Port Forwarding
Application port forwarding is configured for thin-client mode SSL VPN. Port forwarding extends the cryptographic functions of the SSL-protected browser to provide remote access to TCP and UDP-based applications that use well-known port numbers, such as POP3, SMTP, IMAP, Telnet, and SSH.
When port forwarding is enabled, the hosts file on the SSL VPN client is modified to map the application to the port number configured in the forwarding list. The application port mapping is restored to default when the user terminates the SSL VPN session.
When you are enabling port forwarding, the SSL VPN gateway will modify the hosts file on the PC of the remote user. Some software configurations and software security applications will detect this modification and prompt the remote user to choose "Yes" to permit. To permit the modification, the remote user must have local administrative privileges.
There is a known compatibility issue with the encryption type and Java. If the Java port-forwarding applet does not download properly and the configuration line sslencryption3des-sha1aes-sha1 is present, you should remove the line from the WebVPN gateway subconfiguration.
Before You Begin
SSL VPN gateway and SSL VPN context configurations are enabled and operational.
Remaps (forwards) an application port number in a port forwarding list.
The remote port number is the well-known port to which the application listens. The local port number is the entry configured in the port forwarding list. A local port number can be configured only once in a given port forwarding list.
Step 6
exit
Example:
Router(config-webvpn-port-fwd)# exit
Exits WebVPN port-forward list configuration mode, and enters WebVPN context configuration mode.
Step 7
policygroupname
Example:
Router(config-webvpn-context)# policy group ONE
Enters WebVPN group policy configuration mode to configure a group policy.
Step 8
port-forwardname
Example:
Router(config-webvpn-group)# port-forward EMAIL
Attaches a port forwarding list to a policy group configuration.
Configuring the SSL VPN Gateway to Distribute CSD and Cisco AnyConnect VPN Client Package Files
The SSL VPN gateway is preconfigured to distribute Cisco Secure Desktop (CSD) or Cisco AnyConnect VPN Client software package files to remote users. The files are distributed only when CSD or Cisco AnyConnect VPN Client support is needed. The administrator performs the following tasks to prepare the gateway:
The current software package is downloaded from www.cisco.com.
The package file is copied to a local file system.
The package file is installed for distribution by configuring the
webvpn install command.
The remote user must have administrative privileges, and the JRE for Windows version 1.4 or later must be installed before the CSD client package can be installed.
For Cisco AnyConnect VPN Client software installation, the remote user must have either the Java Runtime Environment for Windows (version 1.4 or later), or the browser must support or be configured to permit Active X controls.
CSD and Cisco AnyConnect VPN Client software packages should be installed for distribution on the SSL VPN gateway. Download the latest version that supports your device and the image you are using (consult a compatibility matrix for your particular setup).
The CSD software package can be downloaded at the following URL:
Support for CSD and Cisco AnyConnect VPN Client can be enabled for remote users after the gateway has been prepared to distribute CSD or Cisco AnyConnect VPN Client software.
Configuring Cisco Secure Desktop Support
CSD provides a session-based interface where sensitive data can be shared for the duration of an SSL VPN session. All session information is encrypted. All traces of the session data are removed from the remote client when the session is terminated, even if the connection is terminated abruptly. CSD support for remote clients is enabled in this task.
The remote user (PC or device) must have administrative privileges, and the JRE for Windows version 1.4 or later must be installed before the CSD client packages can be installed.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
The CSD software package is installed for distribution on the SSL VPN gateway.
Upon completion of this task, the SSL VPN gateway has been configured to provide clientless and thin-client support for remote users. The SSL VPN feature also has the capability to provide full VPN access (similar to IPsec). Proceed to the Configuring Cisco AnyConnect VPN Client Full Tunnel Support to see more information.
Configuring Cisco AnyConnect VPN Client Full Tunnel Support
The Cisco AnyConnect VPN Client is an application that allows a remote user to establish a full VPN connection similar to the type of connection that is established with an IPsec VPN. Cisco AnyConnect VPN Client software is pushed (downloaded) and installed automatically on the PC of the remote user. The Cisco AnyConnect VPN Client uses SSL to provide the security of an IPsec VPN without the complexity required to install IPsec in your network and on remote devices. The following tasks are completed in this configuration:
An access list is applied to the tunnel to restrict VPN access.
Cisco AnyConnect VPN Client tunnel support is enabled.
An address pool is configured for assignment to remote clients.
The default domain is configured.
DNS is configured for Cisco AnyConnect VPN Client tunnel clients.
Dead peer timers are configured for the SSL VPN gateway and remote users.
The login home page is configured.
The Cisco AnyConnect VPN Client software package is configured to remain installed on the remote client.
Tunnel key refresh parameters are defined.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
The Cisco AnyConnect VPN Client software package is installed for distribution on the SSL VPN gateway.
The remote client has administrative privileges. Administrative privileges are required to download the SSL VPN software client.
Entering the
svc-enabled keyword enables tunnel support for the remote user. If the Cisco AnyConnect VPN Client software package fails to install, the remote user can continue to use clientless mode or thin-client mode.
Entering the
svc-required keyword enables only tunnel support for the remote user. If the Cisco AnyConnect VPN Client software package fails to install (on the PC of the remote user), the other access modes cannot be used.
Configures a pool of IP addresses to assign to remote users in a policy group.
The address pool is first defined with the
iplocalpool command in global configuration mode.
If you are configuring an address pool for a network that is not direc tly connected, an address from the pool must be configured on a locally loopback interface. See the third example at the end of this section.
Configures the dead peer detection (DPD) timer value for the gateway or client.
The DPD timer is reset every time a packet is received over the SSL VPN tunnel from the gateway or remote user.
Step 11
svckeepaliveseconds
Example:
Router(config-webvpn-group)# svc keepalive 300
(Optional) Enables the SVC to send keepalive messages by default with a frequency of 30 seconds.
Use this command to adjust the frequency of keepalive messages to ensure that an SVC connection through a proxy, Cisco IOS firewall, or NAT device remains active, even if the device limits the time that the connection can be idle. Adjusting the frequency also ensures that the SVC does not disconnect and reconnect when the remote user is not actively running a socket-based application, such as Microsoft Outlook or Microsoft Internet Explorer.
If the
svckeepalive command is configured with a value of
0 seconds, then the keepalive function is disabled.
The following example, starting in global configuration mode, configures a deny access filter for any host from the 172.16.2/24 network:
Router(config)# access-list 101 deny ip 172.16.2.0 0.0.0.255 any
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# filter tunnel 101
Router(config-webvpn-group)# end
Address Pool (Directly Connected Network) Configuration
The following example, starting in global configuration mode, configures the 192.168.1/24 network as an address pool:
Router(config)# ip local pool ADDRESSES 192.168.1.1 192.168.1.254
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# svc address-pool ADDRESSES
Router(config-webvpn-group)# end
Address Pool (Nondirectly Connected Network) Configuration
The following example, starting in global configuration mode, configures the 172.16.1/24 network as an address pool. Because the network is not directly connected, a local loopback interface is configured.
Router(config)# interface loopback 0
Router(config-int)# ip address 172.16.1.126 255.255.255.0
Router(config-int)# no shutdown
Router(config-int)# exit
Router(config)# ip local pool ADDRESSES 172.16.1.1 172.16.1.254
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# svc address-pool ADDRESSES
Router(config-webvpn-group)# end
Full Tunnel Configuration
The following example, starting in global configuration mode, configures full Cisco AnyConnect VPN Client tunnel support on an SSL VPN gateway:
This section describes advanced Cisco AnyConnect VPN Client tunnel configurations. The following configuration steps are completed in this task:
Split tunnel support and split DNS resolution are enabled on the SSL VPN gateway.
SSL VPN gateway support for Microsoft Internet Explorer proxy settings is configured.
WINS resolution is configured for Cisco AnyConnect VPN Client tunnel clients.
Microsoft Internet Explorer Proxy Configuration--The SSL VPN gateway can be configured to pass or bypass Microsoft Internet Explorer (MSIE) proxy settings. Only HTTP proxy settings are supported by the SSL VPN gateway. MSIE proxy settings have no effect on any other supported browser.
Split Tunneling--Split tunnel support allows you to configure a policy that permits specific traffic to be carried outside of the Cisco AnyConnect VPN Client tunnel. Traffic is either included (resolved in tunnel) or excluded (resolved through the Internet service provider [ISP] or WAN connection). Tunnel resolution configuration is mutually exclusive. An IP address cannot be both included and excluded at the same time. Entering the
local-lans keyword permits the remote user to access resources on a local LAN, such as network printer.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
The Cisco AnyConnect VPN Client software package is installed for distribution on the SSL VPN gateway.
Note
Only Microsoft Windows 2000, Windows XP, Windows Vista, Apple-Mac, and Linux are supported on the remote client.
Configures split tunneling for policy group remote users.
Split tunneling is configured to include or exclude traffic in the Cisco AnyConnect VPN Client tunnel. Traffic that is included is sent over the SSL VPN tunnel. Excluded traffic is resolved outside of the tunnel.
Exclude and include statements are configured with IP address/wildcard mask pairs.
Step 6
svcsplitdnsname
Example:
Router(config-webvpn-group)# svc split dns www.examplecompany.com
Configures the SSL VPN gateway to resolve the specified fully qualified DNS names through the Cisco AnyConnect VPN Client tunnel.
A default domain was configured in the previous task with the
svcdefault-domain command. DNS names configured with the
svcsplitdns command are configured in addition.
The following example, starting in global configuration mode, configures the following DNS names to be resolved in the Cisco AnyConnect VPN Client tunnel:
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# svc split dns www.example.com
Router(config-webvpn-group)# svc split dns myexample.com
Including and Excluding IP Prefixes
The following example configures a list of IP addresses to be resolved over the tunnel (included) and a list to be resolved outside of the tunnel (excluded):
VRF Virtualization allows you to associate a traditional VRF with an SSL VPN context configuration. This feature allows you to apply different configurations and reuse address space for different groups of users in your organization.
Before You Begin
A VRF has been configured in global configuration mode.
SSL VPN gateway and context configurations are enabled and operational.
A policy group has been configured and associated with the WebVPN context.
Note
Only a single VRF can be configured for each SSL VPN context configuration.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpncontextname
4.vrf-namename
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpncontextname
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 4
vrf-namename
Example:
Router(config-webvpn-context)# vrf-name vrf1
Associates a VRF with an SSL VPN context.
Note
When you configure the VRF Virtualization feature in Cisco IOS Release 12.4(24)T1 and later releases, the following message is displayed:
% IP VRF vrf1 configuration applied.
% But please use Virtual-Template to configure VRF.
The ACL rules can be overridden for an individual user when the user logs in to the gateway (using AAA policy attributes). If a user session has no ACL attribute configured, all application requests from that user session are permitted by default.
Before You Begin
Before configuring the ACL rules, you must have first configured the time range using the
time-range command (this prerequisite is in addition to optionally configuring the time range, in the task table, as part of the
permit or
deny entries).
Note
There is no limitation on the maximum number of filtering rules that can be configured for each ACL entry, but keeping the number below 50 should have no significant impact on router performance.
(Optional) Defines a URL as an ACL violation page.
If the
error-url command is configured, the user is redirected to a predefined URL for every request that is not allowed. If the
error-url command is not configured, the user gets a standard, gateway-generated error page.
Step 8
error-msgmessage-string
Example:
Router(config-webvpn-acl)# error-msg "If you have any questions, please contact <a href+mailto:employee1@example.com>Employee1</a>."
(Optional) Displays a specific error message when a user logs in and his or her request is denied.
Step 9
list
Example:
Router(config-webvpn-acl)# list
(Optional) Lists the currently configured ACL entries sequentially and assigns a position number.
Associating an ACL Attribute with a Policy Group
Note
Associating an ACL attribute for an individual user must be performed as part of a AAA operation.
The ACL rules can be overridden for an individual user when the user logs in to the gateway (using AAA policy attributes).
If a user session has no ACL attribute configured, all application requests from that user session are permitted by default.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpncontextname
4.policygroupname
5.exit
6.aclacl-name
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpncontextname
Example:
Router(config)# webvpn context context1
Configures the SSL VPN context and enters WebVPN context configuration mode.
Step 4
policygroupname
Example:
Router(config-webvpn-context)# policy group group1
Defines a policy that can be applied to the user and enters WebVPN policy group configuration mode.
Step 5
exit
Example:
Router(config-webvpn-group)# exit
Exits WebVPN policy group configuration mode.
Step 6
aclacl-name
Example:
Router(config-webvpn-context)# acl acl1
Defines the ACL and enters WebVPN ACL configuration mode.
Configures the SSL VPN context and enters WebVPN context configuration mode.
Step 4
policygroupname
Example:
Router(config-webvpn-context)# policy group ONE
Configures a group policy and enters group policy configuration mode.
Step 5
mask-urls
Example:
Router(config-webvpn-group)# mask-urls
Obfuscates, or masks, sensitive portions of an enterprise URL, such as IP addresses, hostnames, or port numbers.
Adding a CIFS Server URL List to an SSL VPN Context and Attaching It to a Policy Group
Before You Begin
Before adding a CIFS server URL list to an SSL VPN context, you must have already set up the Web VPN context using the
webvpn context command, and you must be in WebVPN context configuration mode.
SUMMARY STEPS
1.cifs-url-listname
2.headingtext-string
3.url-textname
4.exit
5.policygroupname
6.cifs-url-listname
7.exit
8.exit
DETAILED STEPS
Command or Action
Purpose
Step 1
cifs-url-listname
Example:
Router(config-webvpn-context)# cifs-url-list c1
Enters WebVPN URL list configuration mode to configure a list of CIFS server URLs to which a user has access on the portal page of an SSL VPN.
Step 2
headingtext-string
Example:
Router(config-webvpn-url)# heading "cifs-url"
Configures the heading that is displayed above URLs listed on the portal page of an SSL VPN.
To configure FVRF so that the SSL VPN gateway is fully integrated into an MPLS network, perform the following steps.
Before You Begin
As the following configuration task shows, IP VRF must be configured before the FVRF can be associated with the SSL VPN gateway. For more information about configuring IP VRF, see the Configuring IP VRF (ip vrf command) in the
Additional References section.
SUMMARY STEPS
1.enable
2.configureterminal
3.ipvrfvrf-name
4.exit
5.webvpn gatewayname
6.vrfnamename
7.exit
8.exit
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
ipvrfvrf-name
Example:
Router(config)# ip vrf vrf_1
Defines a VPN VRF instance and enters VRF configuration mode.
Note
The
vrf-name argument specified here must be the same as the
name argument in Step 6.
Step 4
exit
Example:
Router(config-vrf)# exit
Exits VRF configuration mode.
Step 5
webvpn gatewayname
Example:
Router(config)# webvpn gateway mygateway
Enters WebVPN gateway configuration mode to configure an SSL VPN gateway.
Step 6
vrfnamename
Example:
Router(config-webvpn-gateway)# vrfname vrf_1
Associates a VPN FVRF with an SSL VPN gateway.
Note
The value for the
name argument here must be the same as the value for the
vrf-name argument in Step 3.
Step 7
exit
Example:
Router(config-webvpn-gateway)# exit
Exits WebVPN gateway configuration mode.
Step 8
exit
Example:
Router(config)# exit
Exits global configuration mode.
Disabling Full-Tunnel Cisco Express Forwarding
Note
The
no webvpn cef command disables all Web VPN Cisco Express Forwarding support, not just full-tunnel Cisco Express Forwarding support.
(Optional) Defines the action for the request to the public website.
direct-access--Provides the user with direct access to the URL. In addition, the user receives an information page stating that he or she can access the URL directly.
redirect--Provides the user with direct access to the URL, but the user does not receive the information page.
Importing the File into the URL List and Binding It to a Policy Group
SUMMARY STEPS
1.enable
2.configure terminal
3.webvpn contextname
4.url-listname
5.importdevice:file
6.exit
7.policy groupgroupname
8.url-listname
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configure terminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpn contextname
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 4
url-listname
Example:
Router(config-webvpn-context)# url-list testlist
Enters WebVPN URL list configuration mode to configure a list of URLs to which a user has access on the portal page of an SSL VPN and attaches the URL list to a policy group.
Step 5
importdevice:file
Example:
Router(config-webvpn-url)# import flash:testlist
Imports the user-defined URL list.
Step 6
exit
Example:
Router(config-webvpn-url)# exit
Exits WebVPN URL list configuration mode.
Step 7
policy groupgroupname
Example:
Router(config-webvpn-context)# policy group policygroup1
Enters WebVPN group policy configuration mode to configure a group policy.
Verifying That the URL List File Was Bound Correctly to the Policy Group
SUMMARY STEPS
1.enable
2.show running-config
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
show running-config
Example:
Router# show running-config
Verifies that the url-list file was bound correctly to the policy group.
Configuring a Virtual Template
A virtual template enables SSL VPN to interoperate with IP features such as NAT, firewall, and policy-based routing.
Before You Begin
SSL VPN gateway and context configurations are enabled and operational.
If a VRF is needed, configure it before creating the virtual template.
If the virtual template is to be associated with a firewall security zone, create the security zone before creating the virtual template.
Note
In order for a virtual template to work with SSL VPN, you must configure theip unnumbered command on the virtual template.
SUMMARY STEPS
1.enable
2.configure terminal
3.interface virtual-templatenumber
4.ip unnumberedtypenumber
5.exit
6.webvpn contextname
7.virtual-templatenumber
8.show webvpn context [name]
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configure terminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interface virtual-templatenumber
Example:
Router(config)# interface virtual-template 200
Creates an interface for the virtual template and enters interface configuration mode.
Step 4
ip unnumberedtypenumber
Example:
Router(config-if)# ip unnumbered GigabitEthernet 0/0
Enables IP processing on an interface without assigning an explicit IP address to the interface.
Thetype and
number arguments specify another interface on which the switch has an assigned IP address. The interface specified cannot be another unnumbered interface.
Step 5
exit
Example:
Router(config-if)# exit
Exits interface configuration mode.
Step 6
webvpn contextname
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Perform this task to configure per-tunnel virtual templates. This task describes how to provide DVTI support for an SSL VPN.
A virtual template is configured with the desired IP features. This virtual template is configured in a WebVPN context on a per-tunnel or per-user basis (because a user will have only one tunnel established at a time). Hence the virtual template configuration is applied on a per-tunnel basis for each SSL VPN full tunnel established in the WebVPN context. This configuration also helps you apply a distinct configuration to each user connecting to the WebVPN context using a AAA server.
The distinct per-user policy configuration is downloaded from the AAA server. This configuration includes group policy attributes and ACLs, and is applied to every user connecting to the WebVPN context on a per-user basis.
If a per-user attribute such as ACL is configured both on the AAA server and the virtual template, then the attribute configured on the AAA server takes precedence. The users logged in to the client computer will have the ACL configuration from the AAA server but will have other configurations, such as firewalls and VRF, from the virtual template. That is, the configuration applied to the users will be a combination of the virtual template configuration and the configuration available on the AAA server.
For example, if IP features such as firewalls, ACLs, and VRF are configured in a virtual template and user attributes such as ACLs are configured on the AAA server, the attributes configured on the AAA server take precedence. The users logged in to the client computer will have the ACL configuration from the AAA server but will have firewall and VRF configurations from the virtual template. That is, the configuration applied to the users will be a combination of virtual templates and AAA, where AAA attributes have a higher priority when there is a configuration conflict.
Associates virtual templates for each full tunnel session.
Step 5
inservice
Example:
Router(config-webvpn-context)# inservice
Enables an SSL VPN context.
Note
If a context is already configured and enabled, then you must disable the context using the noinservice command, specify the virtual template using the virtual-templateinterface-number command, and then enable the SSL VPN context using the inservice command.
Use the following commands to debug any errors that you may encounter when you configure the per-Tunnel Virtual Templates:
debugvtemplate {cloning | error | event}
debugwebvpntunnel
Configuring per-Context Virtual Templates
This task describes how to configure virtual tunnel interface support on a per-context basis.
A virtual template is configured with IP features such as NAT, firewalls, and PBR. This virtual template is configured in a WebVPN context, and enables SSL VPN to interoperate with the IP features configured. This configuration is applied to all users connecting to that WebVPN context.
SUMMARY STEPS
1.enable
2.configureterminal
3.webvpncontextcontext-name
4.virtual-templateinterface-number
5.inservice
6.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpncontextcontext-name
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 4
virtual-templateinterface-number
Example:
Router(config-webvpn-context)# virtual-template 1
Associates a virtual template with an SSL VPN context.
Step 5
inservice
Example:
Router(config-webvpn-context)# inservice
Enables an SSL VPN context.
Note
If a context is already configured and enabled, then you must disable the context using the noinservice command, specify the virtual template using the virtual-templateinterface-number command, and then enable the SSL VPN context using the inservice command.
In order to import the AnyConnect profile to the Cisco IOS headend, the administrator must download the AnyConnect profile from an AnyConnect client (this profile comes by default with AnyConnect), update the UseStartBeforeLogin XML tag available in the profile file to inform AnyConnect to support SBL, and then import the modified profile into the Cisco IOS software.
The secure gateway administrator maintains the AnyConnect profile file and distributes it to the clients.
Following is an extract of the Cisco IOS AnyConnect VPN client profile XML file:
The SBL functionality connects the client PC to the enterprise network even before the users log into the PC. This functionality allows the administrator to run the logon scripts even if the user is not connected to the enterprise network. This is useful for a number of deployment scenarios where the user is outside the physical corporate network and cannot access the resources until his system is connected to the corporate network.
Only an administrator can enable or disable SBL. The end users accessing the client PC are not allowed to enable or disable this functionality.
Before You Begin
SSL VPN must have the ability to import profiles on the Cisco IOS software and must be able to send the AnyConnect profile to the client.
Imports the AnyConnect profile to the Cisco IOS headend.
Step 4
webvpn contextcontext-name
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 5
policy groupgroup-name
Example:
Router(config-webvpn-context)# policy group group1
Enters WebVPN group policy configuration mode to configure a group policy.
Step 6
svc profileprofile-name
Example:
Router(config-webvpn-group)# svc profile profile1
Applies the concerned profile to the respective WebVPN group policy.
Step 7
svc modulemodule-name
Example:
Router(config-webvpn-group)# svc module vpngina
Enables the SBL functionality support for the Cisco IOS SSL VPN headend.
Note
Only the vpngina SVC module is supported.
Step 8
end
Example:
Router(config-webvpn-group)# end
Exits WebVPN group policy configuration mode.
Note
You must restart your system for the SBL functionality to take effect.
Step 9
show running-config
Example:
Router# show running-config
(Optional) Displays the contents of the current running configuration file or the configuration for a specific module, Layer 2 VLAN, class map, interface, map class, policy map, or virtual circuit (VC) class.
Use the debugwebvpncookie command to debug any errors that you may encounter when you configure the SBL functionality.
Configuring Split ACL Support
Perform this task to configure split ACL support.
When the tunnel is active, Cisco IOS SSL VPN supports the
splitinclude and
splitexclude commands to filter and classify the traffic based on IP. Because the Cisco IOS software supports ACLs to classify the traffic, standard ACL support is provided to filter the traffic.
Defines an IP access list or object group access control list (OGACL) by name or number and enters the standard ACL configuration mode.
Step 4
permitip-address
Example:
Router(config-std-nacl)# permit 10.0.0.1
Sets conditions to allow packets to pass a named SSL VPN access list.
Note
You can use the
permit and
deny commands in any combination, as required.
Step 5
denyip-address
Example:
Router(config-std-nacl)# deny 10.0.0.2
Sets conditions in a named SSL VPN access list that will deny packets.
Note
You can use the
permit and
deny commands in any combination, as required.
Step 6
exit
Example:
Router(config-std-nacl)# exit
Exits standard ACL configuration mode.
Step 7
webvpncontextcontext-name
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 8
policygrouppolicy-name
Example:
Router(config-webvpn-context)# policy group default
Enters WebVPN group policy configuration mode to configure a group policy.
Step 9
svcsplit {include |
exclude}
aclacl-list-name
Example:
Router(config-webvpn-group)# svc split include acl 1
Enables split tunneling for Cisco AnyConnect VPN Client tunnel clients.
Step 10
end
Example:
Router(config-webvpn-group)# end
Exits WebVPN group policy configuration mode.
Step 11
showrunning-config
Example:
Router# show running-config
(Optional) Displays the contents of the current running configuration file or the configuration for a specific module, Layer 2 VLAN, class map, interface, map class, policy map, or virtual circuit (VC) class.
Configuring IP NetMask Functionality
The IP NetMask functionality provides SVC or AnyConnect client provision to configure the network mask when the
ip local pool command is configured on the router. This mask must be a classless mask.
SUMMARY STEPS
1.enable
2.configure terminal
3.webvpn contextcontext-name
4.policy groupgroup-name
5.svcaddress-poolpool-namenetmaskip-netmask
6.end
7.showrunning-config
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configure terminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
webvpn contextcontext-name
Example:
Router(config)# webvpn context context1
Enters WebVPN context configuration mode to configure the SSL VPN context.
Step 4
policy groupgroup-name
Example:
Router(config-webvpn-context)# policy group default
Enters WebVPN group policy configuration mode to configure a group policy.
(Optional) Displays the contents of the current running configuration file or the configuration for a specific module, Layer 2 VLAN, class map, interface, map class, policy map, or virtual circuit (VC) class.
Configuring the DTLS Port
DTLS listens on port 443 by default. Perform this task to configure the desired DTLS port.
The following output example shows that HTTP proxy has been configured and that the portal (home) page from URL "http://www.example.com" will automatically download the home page of the user:
The following example attaches the server list to and enables full file and network access permissions for policy group ONE:
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# nbns-list SERVER_LIST
Router(config-webvpn-group)# functions file-access
Router(config-webvpn-group)# functions file-browse
Router(config-webvpn-group)# functions file-entry
Router(config-webvpn-group)# end
Example: Configuring Citrix Application Support for Clientless Remote Access
The following example, starting in global configuration mode, enables Citrix application support for remote users with a source IP address in the 192.168.1.0/24 network:
Router(config)# access-list 100 permit ip 192.168.1.0 0.255.255.255 any
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group ONE
Router(config-webvpn-group)# citrix enabled
Router(config-webvpn-group)# filter citrix 100
Example: Configuring Application Port Forwarding
The following example, starting in global configuration mode, configures port forwarding for well-known e-mail application port numbers:
The following example, starting in global configuration mode, associates the VRF under the SSL VPN context configuration:
Router(config)# ip vrf vrf1
Router(config-vrf)# rd 10.100.100.1:1
Router(config-vrf)# exit
Router(config)# webvpn context context1
Router(config-webvpn-context)# policy group group1
Router(config-webvpn-group)# exit
Router(config-webvpn-context)# default-group-policy policy1
Router(config-webvpn-context)# vrf-name vrf2
Router(config-webvpn-context)# end
When you configure the VRF Virtualization feature in Cisco IOS Release 12.4(24)T1 and later releases, the following message is displayed:
% IP VRF vrf1 configuration applied.
% But please use Virtual-Template to configure VRF.
See the
SSLVPN DVTI Support for an example on how to use a virtual template to configure a VRF.
Example: RADIUS Accounting for SSL VPN Sessions
The following example shows that RADIUS accounting has been configured for SSL VPN user sessions:
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname host1
!
aaa new-model
!
!
aaa accounting network SSL VPNaaa start-stop group radius
aaa accounting update periodic 1
aaa session-id common
ip subnet-zero
ip cef
!
!
no ip domain lookup
ip domain name cisco.com
ip name-server 172.16.2.133
ip name-server 172.16.11.48
!
line con 0
exec-timeout 0 0
line aux 0
line vty 0 4
!
!
webvpn gateway GW1
ip address 172.19.216.141 port 443
inservice
!
webvpn gateway SSL VPN
no inservice
!
webvpn install svc flash:/webvpn/svc.pkg
webvpn aaa accounting-list SSL VPNaaa
!
webvpn context Default_context
ssl encryption
ssl authenticate verify all
!
no inservice
!
!
Example: URL Obfuscation (Masking)
The following output example shows that URL obfuscation (masking) has been configured for policy group "gp_urlobf."
!
!
policy group gp_urlobf
mask-urls
default-group-policy gp_urlobf
gateway gw domain dom
inservice
!
!
Example: Adding a CIFS Server URL List and Attaching It to a Policy List
The following example shows that the CIFS server URLs "SSLVPN-SERVER2" and "SSL-SERVER2" have been added as portal page URLs to which a user has access. The example also shows that the two servers are attached to a policy group.
The following output example shows how to configure an SSL VPN that includes most of the features that are available using SSL VPN:
hostname sslvpn
!
!
aaa new-model
!
!
aaa authentication login default local group radius
!
!
crypto pki trustpoint Gateway
enrollment selfsigned
ip-address 192.168.22.13
revocation-check crl
rsakeypair KeyPair1 2048 2048
!
!
crypto pki certificate chain Gateway
certificate self-signed 02
!
!
interface Loopback0
ip address 10.10.10.1 255.255.255.0
!
!
interface GigabitEthernet0/1
ip address 192.168.22.14 255.255.255.0 secondary
ip address 192.168.22.13 255.255.255.0
duplex auto
speed auto
media-type rj45
!
!
ip local pool svc-pool 10.10.10.100 10.10.10.110
!
!
ip radius source-interface FastEthernet1/1
!
!
webvpn gateway ssl-vpn
ip address 192.168.22.13 port 443
http-redirect port 80
ssl trustpoint Gateway
inservice
!
! The following line is required for SSLVPN Client.
webvpn install svc flash:/webvpn/svc.pkg
!
! The following line is required for Cisco Secure Desktop.
webvpn install csd flash:/webvpn/sdesktop.pkg
!
webvpn context ssl-vpn
ssl authenticate verify all
!
url-list "sslvpn-dt"
url-text "sslvpn-dt" url-value "http://10.1.1.40"
url-text "Exchange Server" url-value "http://10.1.1.40/exchange"
!
sso-server "netegrity"
web-agent-url "http://10.1.1.37/vpnauth/"
secret-key "sslvpn1"
retries 3
timeout 15
!
nbns-list cifs
nbns-server 10.1.1.40
!
port-forward "mail_test"
local-port 30016 remote-server "example1.com" remote-port 143 description "IMAP-test"
local-port 30017 remote-server "example2.com" remote-port 110 description "POP3-test"
local-port 30018 remote-server "example3.com" remote-port 25 description "SMTP-test"
!
policy group default
! The following line applies the URL list.
url-list "sslvpn-dt"
! The following line applies TCP port forwarding.
port-forward "mail_test"
! The following line applies CIFS.
nbns-list "cifs"
! The following line enables CIFS functionality.
functions file-access
! The following line enables CIFS functionality.
functions file-browse
! The following line enables CIFS functionality.
functions file-entry
! The following line enables SSLVPN Client.
functions svc-enabled
! The following line enables clientless Citrix.
citrix enabled
default-group-policy default
! The following line maps this context to the virtual gateway and defines the domain to use.
gateway ssl-vpn domain sslvpn
! The following line enables Cisco Secure Desktop.
csd enable
inservice
!
!
end
The following output example from the
show webvpn stats command shows information about Cisco Express Forwarding-processed packets:
Router# show webvpn stats
User session statistics:
Active user sessions : 56 AAA pending reqs : 0
Peak user sessions : 117 Peak time : 00:13:19
Active user TCP conns : 0 Terminated user sessions : 144
Session alloc failures : 0 Authentication failures : 0
VPN session timeout : 0 VPN idle timeout : 0
User cleared VPN sessions : 0 Exceeded ctx user limit : 0
Exceeded total user limit : 0
Client process rcvd pkts : 1971 Server process rcvd pkts : 441004
Client process sent pkts : 921291 Server process sent pkts : 2013
Client CEF received pkts : 1334 Server CEF received pkts : 951610
Client CEF rcv punt pkts : 0 Server CEF rcv punt pkts : 779
Client CEF sent pkts : 1944439 Server CEF sent pkts : 0
Client CEF sent punt pkts : 21070 Server CEF sent punt pkts : 0
The following example shows that three AnyConnect VPN Client packages have been installed to a gateway and shows the resulting
show webvpn install command output:
Router(config)# webvpn install svc vpn1_i386-Release-2.0.0077-k9.pkg sequence 6
Router(config)# webvpn install svc vpn2_powerpc-Release-2.0.0077-k9.pkg sequence 8
Router(config)# webvpn install svc svc_1.pkg sequence 4
Router# show webvpn install status svc
SSLVPN Package SSL-VPN-Client version installed:
CISCO STC win2k+
2,0,0148
Fri 12/29/2006 19:13:56.37
SSLVPN Package SSL-VPN-Client version installed:
CISCO STC Darwin_i386
2,0,0
Wed Nov 8 04:01:57 MST 2006
SSLVPN Package SSL-VPN-Client version installed:
CISCO STC Darwin_powerpc
2,0,0
Wed Nov 8 03:54:50 MST 2006
The following example shows that three AnyConnect VPN client packages have been configured and typical output from the
show running-config command:
The following example shows that local authorization has been configured:
aaa new-model
!
aaa authentication login default local
aaa authorization network default local
!
aaa attribute list l2
attribute type banner "user2"
!
aaa attribute list l1
attribute type banner "user1"
attribute type urllist-name "my-url-list"
!
username user1 password 0 passwd1
username user1 aaa attribute list l1
username user2 password 0 passwd2
username user2 aaa attribute list l2
!
webvpn context best
ssl authenticate verify all
!
url-list "my-url-list"
heading "external url"
url-text "example" url-value "http://www.example.com"
!
policy group default
default-group-policy default
aaa authorization list default
gateway public domain d1
inservice
Example: URL Rewrite Splitter
The following example shows that URL mangling has been configured for a specific host and IP address. The unmatched action has been defined as direct access.
The following example shows that a backend HTTP proxy has been configured:
webvpn context e1
!
policy group g1
http proxy-server "192.0.2.0" port 2034
default-group-policy g1
Example: Stateless High Availability with HSRP
The figure below shows the topology of a typical stateless high availability with HSRP setup. Router 1 and Router 2 are configured for HSRP on gateway Webvpn. The example following the figure below shows the actual configuration.
Figure 15
Stateless High Availability with HSRP Setup
Router 1 Configuration
Router(config)# interface gateway 0/1
Router(config-if)# standby 0 ip 10.1.1.1
Router(config-if)# standby 0 name SSLVPN
Route(config-if)# exit
Router(config)# webvpn gateway Webvpn
Router(config-webvpn-gateway)# ip address 10.1.1.1 port 443 standby SSLVPN
Router 2 Configuration
Router(config)# interface gateway 0/0
Router(config-if)# standby 0 ip 10.1.1.1
Router(config-if)# standby 0 name SSLVPN2
Router(config-if)# exit
Router(config)# webvpn gateway Webvpn
Router(config-webvpn-gateway)# ip address 10.1.1.1 port 443 standby SSLVPNigh2
The following is an example of a generated browser attribute template:
<?xml version="1.0" encoding="utf-8"?>
<!--
- Template file for browser attributes import
<color> - primary color
<scolor> - secondary color
<tcolor> - text color
<stcolor> - secondary text color
<lmsg> - login message
<title> - browser title
<ticolor> - title color
Default value will be used if the field is not defined
Copyright (c) 2007-2008 by Cisco Systems, Inc. All rights reserved.
-->
<settings>
<color>#003333</color>
<scolor>#336666</scolor>
<tcolor>white</tcolor>
<stcolor>black</stcolor>
<lmsg>Welcome to<p>Cisco Systems WebVPN Service</lmsg>
<title>WebVPN Service</title>
<ticolor>#003333</ticolor>
</settings>
Example: Copying the Browser Attribute File to Another PC for Editing
The following example shows how to copy a browser attribute file to another PC for editing:
Router# copy flash: tftp:
Source filename [battr_tpl.xml
]?
Address or name of remote host []? 10.1.1.30
Destination filename [battr_tpl.xml
]?
!!
677 bytes copied in 0.004 secs (169250 bytes/sec)
Example: Copying the Edited File to flash
The following example shows how to copy an edited attribute file to flash:
The followingshow running-config command output shows that URL list file has been imported into the url-list and that it has been bound to the policy group:
Router# show running-config
policy group default
url-list "test"
functions file-access
functions file-browse
functions file-entry
functions svc-enabled
mask-urls
svc address-pool "mypool"
svc keep-client-installed
svc split include 10.1.1.0 255.255.255.0
default-group-policy default
gateway g
language customize mylang flash:lang.js
inservice
Example: Virtual Template
The following configuration and output examples display various aspects of the virtual template feature. The following example, starting in global configuration mode, creates a virtual template and associates it with an SSL VPN context configuration. It also configures the virtual template for VRF and NAT:
Router(config)# interface virtual-template 100
Router(config-if)# ip unnumbered GigabitEthernet 0/0
Router(config-if)# ip vrf forwarding vrf1
Router(config-if)# ip nat inside
Router(config-if)# exit
Router(config)# webvpn context context1
Router(config-webvpn-context)# virtual-template 100
Router(config-webvpn-context)# exit
The following example creates a virtual template and associates it with a security zone:
The figure below shows an example network where remote users User1 and User2 belong to a context called Context1, User3 belongs to a context called Context2, and they connect to the SSL VPN gateway and access the backend server in the corporate network.
Example: Configuring in the per-Tunnel Context Using Virtual Templates
The following example shows how to apply VRF, a firewall policy, and ACLs to each user based on the virtual template configuration.
If the VRF, firewall policy, and ACL features are configured in the virtual template and user policies are not configured on the AAA server, then only the IP features configured in the virtual template are applied to the users. In this example, User1 and User2 belonging to Context1 have zone1, vrf1, and ACL 1 configured whereas User3 belonging to Context2 has zone3, vrf3, and ACL 3 configured. Hence, different users have different IP features configured.
Virtual Template for User1 and User2
configure terminal
interface virtual-template 1
zone-member security zone1
ip vrf forwarding vrf1
ip access-group 1 in
ip unnumbered GigabitEthernet 0/1
Virtual Template for User3
configure terminal
interface virtual-template 3
zone-member security zone3
ip vrf forwarding vrf3
ip access-group 3 in
ip unnumbered GigabitEthernet 0/1
Example: Configuring in the per-Tunnel Context Using Virtual Templates and a AAA Server
The following example shows how to apply the IP feature configuration to the users based on the user-specific configuration available on the AAA server. The user-specific attributes configured on the AAA server are applied to the users when an SSL VPN session establishes a virtual tunnel. The configuration applied to the users will be a combination of the configurations in the virtual template and the AAA server, where AAA attributes have a higher priority when there is a configuration conflict.
In this example, ACL 1 is configured for User1, ACL 2 is configured for User2, and ACL 3 is configured for User3 on the AAA server using theinacl attribute. Even though ACL 4 is applied to all the users in the virtual template, User1 has ACL 1, User2 has ACL 2, and User3 has ACL 3 configured along with zone and VRF configurations available in the virtual template.
Virtual Template for User1 and User2
configure terminal
interface virtual-template 1
zone-member security zone1
ip vrf forwarding vrf1
ip access-group 4 in
ip unnumbered GigabitEthernet 0/1
Virtual Template for User3
configure terminal
interface virtual-template 3
zone-member security zone3
ip vrf forwarding vrf3
ip access-group 4 in
ip unnumbered GigabitEthernet 0/1
The following figure shows remote users User1 and User2 belonging to context1 and User3 belonging to context2, connecting to the SSL VPN gateway and accessing the backend server in the corporate network. Here, the IP feature configuration is applied to each user based on the configuration applied to the WebVPN context of the user.
Figure 17
Topology Showing a per-Context Virtual Template
The following example shows how to apply VRF and a firewall policy to each user based on the WebVPN context of the user. In this example, User1 and User 2 connected to Context1 have zone1 and vrf1 configured on the virtual template 1, and User3 connected to Context2 has zone2 and vrf2 configured on virtual template 2.
Virtual Template for User1
configure terminal
interface virtual-template 1
zone-member security zone1
ip vrf forwarding vrf1
ip unnumbered GigabitEthernet 0/1
Virtual Template for User2
configure terminal
interface virtual-template 2
zone-member security zone2
ip vrf forwarding vrf2
ip unnumbered GigabitEthernet 0/1
Example: Configuring the Start Before Logon Functionality
The following example shows how to configure SBL functionality:
enable
configure terminal
webvpn import svc profile profile1 flash:newName
policy group group1
svc profile profile1
end
Example: Configuring Split ACL Support
The following example shows how to configure split ACL support:
enable
configure terminal
ip access-list standard 1
permit 10.0.0.1
deny 10.0.0.2
exit
webvpn context context1
policy group policy1
svc split include acl 1
end
Example: Configuring IP NetMask Functionality
The following example shows how to configure IP netmask functionality:
enable
configure terminal
webvpn context context1
policy group policy1
svc address-pool pool1 netmask 255.255.0.0
end
The following is sample output from the
show webvpn context command:
Router# show webvpn context
Codes: AS - Admin Status, OS - Operation Status
VHost - Virtual Host
Context Name Gateway Domain/VHost VRF AS OS
------------ ------- ------------ ------- ---- --------
Default_context n/a n/a n/a down down
con-1 gw-1 one - up up
con-2 - - - down down
Example: show webvpn context name
The following is sample output from the
show webvpn context command, entered with the name of a specific SSL VPN context:
Router# show webvpn context context1
Admin Status: up
Operation Status: up
CSD Status: Disabled
Certificate authentication type: All attributes (like CRL) are verified
AAA Authentication List not configured
AAA Authentication Domain not configured
Default Group Policy: PG_1
Associated WebVPN Gateway: GW_ONE
Domain Name: DOMAIN_ONE
Maximum Users Allowed: 10000 (default)
NAT Address not configured
VRF Name not configured
Example: show webvpn gateway
The following is sample output from the
showwebvpngateway command:
Router# show webvpn gateway Gateway Name Admin Operation------------ ----- ---------GW_1 up up GW_2 down down
Example: show webvpn gateway name
The following is sample output from the
show webvpn gateway command, entered with a specific SSL VPN gateway name:
Router# show webvpn gateway GW_1
Admin Status: up
Operation Status: up
IP: 10.1.1.1, port: 443
SSL Trustpoint: TP-self-signed-26793562
Example: show webvpn install file
The following is sample output from the
show webvpn install command, entered with the
file keyword:
The following is sample output from the
show webvpn install
command, entered with the
status svc keywords:
Router# show webvpn install status svc
SSL VPN Package SSL-VPN-Client version installed:
CISCO STC win2k+ 1.0.0
1,0,2,127
Fri 07/22/2005 12:14:45.43
Example: show webvpn nbns context all
The following sample output from the
show webvpn nbns command, entered with the
context all keywords:
Router# show webvpn nbns context all
NetBIOS name IP Address Timestamp
0 total entries
NetBIOS name IP Address Timestamp
0 total entries
NetBIOS name IP Address Timestamp
0 total entries
Example: show webvpn policy
The following is sample output from the
show webvpn policy command:
The following is sample output from the
show webvpn session command. The output is filtered to display user session information for only the specified context.
The following output example shows that FVRF has been configured:
Router# show webvpn gateway mygateway
Admin Status: down
Operation Status: down
Error and Event Logging: Disabled
GW IP address not configured
SSL Trustpoint: TP-self-signed-788737041
FVRF Name: vrf_1
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 6
Feature Information for SSL VPN
Feature Name
Release
Feature Information
Access Control Enhancements
12.4(20)T
This feature allows administrators to configure automatic authentication and authorization for users. Users provide their usernames and passwords via the gateway page URL and do not have to reenter their usernames and passwords from the login page. Authorization is enhanced to support more generic authorization, including local authorization.
The following commands were introduced by this feature:
aaa authentication auto, aaa authorization list.
AnyConnect Client Support
12.4(20)T
Effective with this release, AnyConnect Client adds support for several client-side platforms, such as Microsoft Windows, Apple-Mac, and Linux. The ability to install AnyConnect in a standalone mode is also added. In addition, this feature allows multiple SSL VPN client package files to be configured on a gateway.
The following command was modified by this feature:
webvpn install.
Application ACL Support
12.4(11)T
This feature provides administrators with the flexibility to fine-tune access control at the application layer level.
The following commands were introduced by this feature:
acl add error-msg, error-url, list.
Auto Applet Download
12.4(9)T
This feature provides administrators with the option of automatically downloading the port-forwarding applet under the policy group.
The following command was modified by this feature:
port-forward (policy group).
Backend HTTP Proxy
12.4(20)T
This feature allows administrators to route user requests through a backend HTTP proxy, providing more flexibility and control than routing through internal web servers.
The following command was added by this feature:
http proxy-server.
Cisco AnyConnect VPN Client
12.4(15)T
This feature is the next-generation SSL VPN Client. The feature provides remote users with secure VPN connections to the router platforms supported by SSL VPN and to the Cisco 5500 Series Adaptive Security Appliances.
Users having Cisco IOS releases before Release 12.4(15)T see
SSL VPN Client GUI. Users having Release 12.4(15)T and later releases see
Cisco AnyConnect VPN Client GUI.
The task configurations in this document for tunnel mode apply to SVC and AnyConnect VPN Client.
Many of the features listed in the documents
Cisco AnyConnect VPN Client Administrator Guide and
Release Notes for Cisco AnyConnect VPN Client, Version 2.0
apply only to the Cisco ASA 5500 Series Adaptive Security Appliances. For a list of features that do not currently apply to other Cisco platforms, see the restriction in the
Cisco AnyConnect VPN Client of this document.
Debug Infrastructure
12.4(11)T
Updates to the
webvpn debug command provide administrators with the ability to turn debugging on for any one user or group.
The following keywords were introduced by this feature:
acl, entry sso, verbose.
The following keyword options were added for the
http keyword:
authentication,
trace, and
verbose.
The
verbose keyword option was added for the
citrix,
cookie,
tunnel, and
webservice keywords.
The
port-forwardkeyword was deleted and the
detail keyword option for thetunnel keyword was deleted.
Front-Door VRF Support
12.4(15)T
Coupled with the already supported internal VRF, this feature allows the SSL VPN gateway to be fully integrated into an MPLS network.
Full-Tunnel CEF Support
12.4(20)T
This feature provides better performance for full-tunnel packets.
GUI Enhancements
12.4(15)T
These enhancements provide updated examples and explanation of the Web VPN GUIs.
Internationalization
12.4(22)T
The Internationalization feature provides multilanguage support for SSL VPN clients, such as Cisco Secure Desktop (CSD) and SSL VPN Client (SVC).
The following commands were introduced:
browser-attribute import, import language, webvpn create template.
Licensing support for Cisco IOS SSL VPNs
15.0(1)M
A license count is associated with each counted license and the count indicates the instances of the feature available for use in the system.
In Cisco IOS Release 15.0(1)M, support was added for Cisco 880, Cisco 890, Cisco 1900, Cisco 2900, and Cisco3900 series routers.
The following commands were introduced or modified:
debug webvpn license, show webvpn license.
Max-user limit message
12.4(22)T
This error message is received when a user tries to log in to a Web VPN context and his or her maximum user limit has been reached.
Netegrity Cookie-Based Single SignOn (SSO) Support
12.4(11)T
This feature allows administrators to configure an SSO server that sets a SiteMinder cookie in the browser of a user when the user initially logs in. The benefit of this feature is that users are prompted to log in only a single time.
The following commands were modified for this feature:
clearwebvpnstats,debugwebvpn,
showwebvpncontext,
showwebvpnpolicy, and
showwebvpnstats.
The following commands were added for this feature:
max-retry-attempts,request-timeout,secret-key,sso-server, and
web-agent-url.
NTLM Authentication
12.4(9)T
This feature provides NT LAN Manager (NTLM) authentication support.
The following command was modified by this feature:
functions.
Port-Forward Enhancements
12.4(11)T
This feature provides administrators with more options for configuring HTTP proxy and portal pages.
The following commands were added for this feature:
acl,add,
deny,error-msg,error-url,list, and
permit.
RADIUS Accounting
12.4(9)T
This feature provides for RADIUS accounting for SSL VPN sessions.
The following command was added by this feature:
webvpnaaaaccounting-list.
SSL VPN
12.4(6)T
This feature enhances SSL VPN support in Cisco IOS software. This feature provides a comprehensive solution that allows easy access to a broad range of web resources and web-enabled applications using native HTTP over SSL (HTTPS) browser support. SSL VPN introduced three modes of SSL VPN access: clientless, thin-client, and full-tunnel client support.
The following command was introduced in Cisco IOS Release 12.4(15)T:
cifs-url-list.
This feature enables SSL VPN to authenticate clients based on the client's AAA username and password and also supports webvpn gateway authentication of clients using AAA certificates.
The following command was modified by this feature:
authenticationcertificate,
catrustpoint,
match-certificate,
svcprofile,
username-prefill,
webvpnimportsvcprofile.
SSLVPN DVTI Support
15.1(1)T
The SSLVPN DVTI Support feature adds DVTI support to the SSLVPN and hence enables seamless interoperability with IP features such as firewalls, NAT, ACL, and VRF. This feature also provides DVTI support, which allows the configuration of IP features on a per-tunnel basis.
The following command was introduced or modified:
virtual-template.
SSL VPN Phase-4 Features
15.1(1)T
The SSL VPN Phase-4 Features feature provides the following enhancements to the Cisco IOS SSL VPN:
ACL support for split tunneling
IP mask for IP pool address assignment
Undoing the renaming of AnyConnect or SVC Full Tunnel Cisco package during installation on a Cisco IOS router
Adding per-user SSL VPN session statistics
Start Before Logon option for the Cisco IOS SSL VPN headend
The following commands were introduced or modified:
showwebvpnsession,
svcaddress-pool,
svcmodule,
svcsplit.
DTLS Support for IOS SSL VPN
15.1(2)T
The DTLS Support for IOS SSL VPN feature enables DTLS as a transport protocol for the traffic tunneled through SSL VPN.
The following commands were introduced or modified:
debug webvpn dtls,
dtls port,
svc dtls.
Stateless High Availability with Hot Standby Router Protocol (HSRP)
12.4(20)T
This feature allows stateless failover to be applied to VPN routers by using HSRP.
The following command was modified by this feature:
ipaddress.
URL Obfuscation
12.4(11)T
This feature provides administrators with the ability to obfuscate, or mask, sensitive portions of an enterprise URL, such as IP addresses, hostnames, or port numbers.
The following command was added by this feature:
mask-urls.
URL Rewrite Splitter
12.4(20)T
This feature allows administrators to selectively mangle requests to the gateway.
The following commands were added by this feature:
host,
ip,
unmatched-action, andurlrewrite.
User-Level Bookmarking
12.4(15)T
This feature allows a user to bookmark URLs while connected through an SSL VPN tunnel.
The following command was added by this feature:
user-profilelocation.
Virtual Templates
12.4(24)T1
A virtual template enables SSL VPN to interoperate with IP features such as NAT, firewall, and policy-based routing.
The following command was introduced:
virtual-template.
Notices
The following notices pertain to this software license.
The OpenSSL toolkit stays under a dual license; that is, both the conditions of the OpenSSL License and the original SSLeay license apply to the toolkit. See below for the actual license texts. Actually both licenses are BSD-style Open Source licenses. In case of any license issues related to OpenSSL please contact openssl-core@openssl.org.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions, and the following disclaimer in the documentation and/or other materials provided with the distribution.
All advertising materials mentioning features or use of this software must display the following acknowledgment: "This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/)".
The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to endorse or promote products derived from this software without prior written permission. For written permission, please contact openssl-core@openssl.org.
Products derived from this software may not be called "OpenSSL" nor may "OpenSSL" appear in their names without prior written permission of the OpenSSL Project.
Redistributions of any form whatsoever must retain the following acknowledgment:
"This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/)".
THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT "AS IS"' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This product includes cryptographic software written by Eric Young (eay@cryptsoft.com). This product includes software written by Tim Hudson (tjh@cryptsoft.com).
This package is an SSL implementation written by Eric Young (eay@cryptsoft.com).
The implementation was written so as to conform with Netscape's SSL.
This library is free for commercial and non-commercial use as long as the following conditions are adhered to. The following conditions apply to all code found in this distribution, be it the RSA, lhash, AES, etc., code; not just the SSL code. The SSL documentation included with this distribution is covered by the same copyright terms except that the holder is Tim Hudson (tjh@cryptsoft.com).
Copyright remains Eric Young's, and as such any Copyright notices in the code are not to be removed. If this package is used in a product, Eric Young should be given attribution as the author of the parts of the library used. This can be in the form of a textual message at program startup or in documentation (online or textual) provided with the package.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
All advertising materials mentioning features or use of this software must display the following acknowledgement:
"This product includes cryptographic software written by Eric Young (eay@cryptsoft.com)".
The word 'cryptographic' can be left out if the routines from the library being used are not cryptography-related.
If you include any Windows specific code (or a derivative thereof) from the apps directory (application code) you must include an acknowledgement: "This product includes software written by Tim Hudson (tjh@cryptsoft.com)".
THIS SOFTWARE IS PROVIDED BY ERIC YOUNG "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
The license and distribution terms for any publicly available version or derivative of this code cannot be changed; that is, this code cannot simply be copied and put under another distribution license [including the GNU Public License].
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL:
www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.