Clientless SSL VPN Remote Users

September 13, 2013

 

This section is for the system administrator who sets up Clientless (browser-based) SSL VPN for end users. It summarizes configuration requirements and tasks for the user remote system. It also specifies information to communicate to users to get them started using Clientless SSL VPN. This section includes the following topics:

Note We assume you have already configured the ASA for Clientless SSL VPN.

Requiring Usernames and Passwords

Depending on your network, during a remote session users may have to log on to any or all of the following: the computer itself, an Internet service provider, Clientless SSL VPN, mail or file servers, or corporate applications. Users may have to authenticate in many different contexts, requiring different information, such as a unique username, password, or PIN. Ensure users have the required access.

Table 18-1 lists the type of usernames and passwords that Clientless SSL VPN users may need to know.

 

Table 18-1 Usernames and Passwords to Give to Clientless SSL VPN Users

Login Username/
Password Type
Purpose
Entered When

Computer

Access the computer

Starting the computer

Internet Service Provider

Access the Internet

Connecting to an Internet service provider

Clientless SSL VPN

Access remote network

Starting a Clientless SSL VPN session

File Server

Access remote file server

Using the Clientless SSL VPN file browsing feature to access a remote file server

Corporate Application Login

Access firewall-protected internal server

Using the Clientless SSL VPN Web browsing feature to access an internal protected website

Mail Server

Access remote mail server via Clientless SSL VPN

Sending or receiving email messages

Communicating Security Tips

Advise users always to log out from the session. To log out of Clientless SSL VPN, click the logout icon on the Clientless SSL VPN toolbar or close the browser.

Advise users that using Clientless SSL VPN does not ensure that communication with every site is secure. Clientless SSL VPN ensures the security of data transmission between the remote computer or workstation and the ASA on the corporate network. If a user then accesses a non-HTTPS Web resource (located on the Internet or on the internal network), the communication from the corporate ASA to the destination Web server is not secure.

Configuring Remote Systems to Use Clientless SSL VPN Features

Table 18-2 includes the following information about setting up remote systems to use Clientless SSL VPN:

  • Starting Clientless SSL VPN
  • Using the Clientless SSL VPN Floating Toolbar
  • Web Browsing
  • Network Browsing and File Management
  • Using Applications (Port Forwarding)
  • Using email via Port Forwarding, Web Access, or Email Proxy

Table 18-2 also provides information about the following:

  • Clientless SSL VPN requirements, by feature
  • Clientless SSL VPN supported applications
  • Client application installation and configuration requirements
  • Information you may need to provide end users
  • Tips and use suggestions for end users

It is possible that you have configured user accounts differently, and that different features are available to each Clientless SSL VPN user. Table 18-2 organizes information by user activity, so that you can skip over the information for unavailable features.

 

Table 18-2 Clientless SSL VPN Remote System Configuration and End User Requirements

Task
Remote System or End User Requirements
Specifications or Use Suggestions

Starting Clientless SSL VPN

Connection to the Internet

Any Internet connection is supported, including:

  • Home DSL, cable, or dial-up
  • Public kiosks
  • Hotel hook-ups
  • Airport wireless nodes
  • Internet cafes

Clientless SSL VPN-supported browser

We recommend the following browsers for Clientless SSL VPN. Other browsers may not fully support Clientless SSL VPN features.

On Microsoft Windows:

  • Internet Explorer 8
  • Firefox 8

On Linux:

  • Firefox 8

On Mac OS X:

  • Safari 5
  • Firefox 8

Cookies enabled on browser

Cookies must be enabled on the browser in order to access applications via port forwarding.

URL for Clientless SSL VPN
An HTTPS address in the following form:
https:// address
where address is the IP address or DNS hostname of an interface of the ASA (or load balancing cluster) on which Clientless SSL VPN is enabled. For example: https://10.89.192.163 or https://cisco.example.com.

Clientless SSL VPN username and password

 

[Optional] Local printer

Clientless SSL VPN does not support printing from a Web browser to a network printer. Printing to a local printer is supported.

Using the Floating Toolbar in a Clientless SSL VPN Connection

 

A floating toolbar is available to simplify the use of Clientless SSL VPN. The toolbar lets you enter URLs, browse file locations, and choose preconfigured Web connections without interfering with the main browser window.

If you configure your browser to block popups, the floating toolbar cannot display.

The floating toolbar represents the current Clientless SSL VPN session. If you click the Close button, the ASA prompts you to close the Clientless SSL VPN session.

Tip To paste text into a text field, use Ctrl-V. (Right-clicking is not enabled on the Clientless SSL VPN toolbar.)

Web Browsing

Usernames and passwords for protected websites

Using Clientless SSL VPN does not ensure that communication with every site is secure. See “Communicating Security Tips.”

 
The look and feel of Web browsing with Clientless SSL VPN may be different from what users are accustomed to. For example:
  • The Clientless SSL VPN title bar appears above each Web page.
  • You access websites by:

– Entering the URL in the Enter Web Address field on the Clientless SSL VPN Home page.

– Clicking on a preconfigured website link on the Clientless SSL VPN Home page.

– Clicking a link on a webpage accessed via one of the previous two methods.

Also, depending on how you configured a particular account, it may be that:
  • Some websites are blocked.
  • Only the websites that appear as links on the Clientless SSL VPN Home page are available.

Network Browsing and File Management

File permissions configured for shared remote access

Only shared folders and files are accessible via Clientless SSL VPN.

Server name and passwords for protected file servers

—

Domain, workgroup, and server names where folders and files reside

Users may not be familiar with how to locate their files through your organization network.

—

Do not interrupt the Copy File to Server command or navigate to a different screen while the copying is in progress. Interrupting the operation can cause an incomplete file to be saved on the server.

Using Applications

(called Port Forwarding or Application Access)

Note On Mac OS X, only the Safari browser supports this feature.

Note Because this feature requires installing Oracle Java Runtime Environment (JRE) and configuring the local clients, and because doing so requires administrator permissions on the local system, it is unlikely that users will be able to use applications when they connect from public remote systems.

Caution Users should always close the Application Access window when they finish using applications by clicking the Close icon. Failure to close the window properly can cause Application Access or the applications themselves to be inaccessible.

Client applications installed

—

Cookies enabled on browser

—

Administrator privileges

User must have administrator access on the computer if you use DNS names to specify servers because modifying the hosts file requires it.

Oracle Java Runtime Environment (JRE) version 1.4.x and 1.5.x installed.

JavaScript must be enabled on the browser. By default, it is enabled.
If JRE is not installed, a pop-up window displays, directing users to a site where it is available.
On rare occasions, the port forwarding applet fails with Java exception errors. If this happens, do the following:

1. Clear the browser cache and close the browser.

2. Verify that no Java icons are in the computer task bar. Close all instances of Java.

3. Establish a Clientless SSL VPN session and launch the port forwarding Java applet.
Client applications configured, if necessary.

Note The Microsoft Outlook client does not require this configuration step.

All non-Windows client applications require configuration.
To see if configuration is necessary for a Windows application, check the value of the Remote Server.
  • If the Remote Server contains the server hostname, you do not need to configure the client application.
  • If the Remote Server field contains an IP address, you must configure the client application.

To configure the client application, use the server’s locally mapped IP address and port number. To find this information:

1. Start Clientless SSL VPN on the remote system and click the Application Access link on the Clientless SSL VPN Home page. The Application Access window appears.

2. In the Name column, find the name of the server to use, then identify its corresponding client IP address and port number (in the Local column).

3. Use this IP address and port number to configure the client application. Configuration steps vary for each client application.

Note Clicking a URL (such as one in an -email message) in an application running over Clientless SSL VPN does not open the site over Clientless SSL VPN. To open a site over Clientless SSL VPN, cut and paste the URL into the Enter (URL) Address field.

Using email
via Application Acces s

Fulfill requirements for Application Access (See Using Applications)
To use mail, start Application Access from the Clientless SSL VPN Home page. The mail client is then available for use.

 

Note If you are using an IMAP client and you lose your mail server connection or are unable to make a new connection, close the IMAP application and restart Clientless SSL VPN.

 

Other email clients

We have tested Microsoft Outlook Express versions 5.5 and 6.0.

Clientless SSL VPN should support other SMTPS, POP3S, or IMAP4S email programs via port forwarding, such as Lotus Notes, and Eudora, but we have not verified them.

Using email via
Web Access

Web-based email product installed

Supported products include:

  • Outlook Web Access

For best results, use OWA on Internet Explorer 8.x or higher, or Firefox 8.x.

  • Lotus Notes

Other web-based email products should also work, but we have not verified them.

 

Using email via
email Proxy

SSL-enabled mail application installed

Do not set the ASA SSL version to TLSv1 Only. Outlook and Outlook Express do not support TLS.

Supported mail applications:

  • Microsoft Outlook
  • Microsoft Outlook Express versions 5.5 and 6.0

Other SSL-enabled mail clients should also work, but we have not verified them.

 

Mail application configured

 

Capturing Clientless SSL VPN Data

The CLI capture command lets you log information about websites that do not display properly over a Clientless SSL VPN connection. This data can help your Cisco customer support engineer troubleshoot problems. The following sections describe how to use the capture command:

Note Enabling Clientless SSL VPN capture affects the performance of the security appliance. Ensure you switch off the capture after you generate the capture files needed for troubleshooting.

Creating a Capture File

DETAILED STEPS

Step 1 To start the Clientless SSL VPN capture utility, use the capture command from privileged EXEC mode.

capture capture-name type webvpn user csslvpn-username

where:

  • capture-name is a name you assign to the capture, which is also prefixed to the name of the capture files.
  • csslvpn-username is the username to match for capture.

The capture utility starts.

Step 2 A user logs in to begin a Clientless SSL VPN session. The capture utility is capturing packets.

Stop the capture by using the no version of the command.

no capture capture-name

The capture utility creates a capture-name .zip file, which is encrypted with the password koleso

Step 3 Send the .zip file to Cisco, or attach it to a Cisco TAC service request.

Step 4 To look at the contents of the .zip file, unzip it using the password koleso .

 

The following example creates a capture named hr , which captures Clientless SSL VPN traffic for user2 to a file:

hostname# capture hr type webvpn user user2
WebVPN capture started.
capture name hr
user name user2
hostname# no capture hr
 

Using a Browser to Display Capture Data

DETAILED STEPS.

Step 1 To start the Clientless SSL VPN capture utility, use the capture command from privileged EXEC mode.

capture capture-name type webvpn user csslvpn-username

where:

  • capture-name is a name you assign to the capture, which is also prefixed to the name of the capture files.
  • csslvpn-username is the username to match for capture.

The capture utility starts.

Step 2 A user logs in to begin a Clientless SSL VPN session. The capture utility is capturing packets.

Stop the capture by using the no version of the command.

Step 3 Open a browser and in the address box enter:

https:// IP address or hostname of the ASA/ webvpn_capture.html

The captured content displays in a sniffer format.

Step 4 When you finish examining the capture content, stop the capture by using the no version of the command.