IP Security VPN Monitoring

Last Updated: September 16, 2011

The IP Security VPN Monitoring feature provides VPN session monitoring enhancements that will allow you to troubleshoot the Virtual Private Network (VPN) and monitor the end-user interface. Session monitoring enhancements include the following:

  • Ability to specify an Internet Key Exchange (IKE) peer description in the configuration file
  • Summary listing of crypto session status
  • Syslog notification for crypto session up or down status
  • Ability to clear both IKE and IP Security (IPsec) security associations (SAs) using one command-line interface (CLI)

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see 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 document.

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 IP Security VPN Monitoring

  • You should be familiar with IPSec and encryption.
  • Your router must support IPSec, and before using the IP Security VPN Monitoring feature, you must have configured IPSec on your router.

Restrictions for IP Security VPN Monitoring

  • You must be running Cisco IOS XE k8 or k9 crypto images on your router.

Information About IPsec VPN Monitoring

Background Crypto Sessions

A crypto session is a set of IPSec connections (flows) between two crypto endpoints. If the two crypto endpoints use IKE as the keying protocol, they are IKE peers to each other. Typically, a crypto session consists of one IKE security association (for control traffic) and at least two IPSec security associations (for data traffic--one per each direction). There may be duplicated IKE security associations (SAs) and IPSec SAs or duplicated IKE SAs or IPSec SAs for the same session in the duration of rekeying or because of simultaneous setup requests from both sides.

Per-IKE Peer Description

The Per-IKE Peer Description function allows you to enter a description of your choosing for an IKE peer. The unique peer description, which can include up to 80 characters, can be used whenever you are referencing that particular IKE peer. To add the peer description, use the description command.


Note
IKE peers that "sit" behind a Network Address Translation (NAT) device cannot be uniquely identified; therefore, they have to share the same peer description.

The primary application of this description field is for monitoring purposes (for example, when using show commands or for logging [syslog messages]). The description field is purely informational (for example, it cannot act as a substitute for the peer address or FQDN when defining crypto maps).

Summary Listing of Crypto Session Status

You can get a list of all the active VPN sessions by entering the show crypto session command. The listing will include the following:

  • Interface
  • IKE peer description, if available
  • IKE SAs that are associated with the peer by whom the IPSec SAs are created
  • IPSec SAs serving the flows of a session

Multiple IKE or IPSec SAs may be established for the same peer (for the same session), in which case IKE peer descriptions will be repeated with different values for the IKE SAs that are associated with the peer and for the IPSec SAs that are serving the flows of the session.

You can also use the show crypto session detail variant of this command to obtain more detailed information about the sessions.

Syslog Notification for Crypto Session Up or Down Status

The Syslog Notification for Crypto Session Up or Down Status function provides syslog notification every time the crypto session comes up or goes down.

The following is a sample syslog notification showing that a crypto session is up:

%CRYPTO-5-SESSION_STATUS: Crypto session is UP. Peer 10.6.6.1:500 fvrf=name10 ivrf=name20  Description: SJC24-2-VPN-Gateway Id: 10.5.5.2

The following is a sample syslog notification showing that a crypto session is down:

%CRYPTO-5-SESSION_STATUS: Crypto session is DOWN. Peer 10.6.6.1:500 fvrf=name10 ivrf=name20 Description: SJC24-2-VPN-Gateway Id: 10.5.5.2

IKE and IPsec Security Exchange Clear Command

The clear crypto session command allows you to clear both IKE and IPsec with a single command. To clear a specific crypto session or a subset of all the sessions (for example, a single tunnel to one remote site), you need to provide session-specific parameters, such as a local or remote IP address, a local or remote port, a front door VPN routing and forwarding (FVRF) name, or an inside VRF (IVRF) name. Typically, the remote IP address will be used to specify a single tunnel to be deleted.

If a local IP address is provided as a parameter when you use the clear crypto session command, all the sessions (and their IKE SAs and IPsec SAs) that share the IP address as a local crypto endpoint (IKE local address) will be cleared. If you do not provide a parameter when you use the clear crypto session command, all IPsec SAs and IKE SAs that are in the router will be deleted.

How to Configure IP Security VPN Monitoring

Adding the Description of an IKE Peer

To add the description of an IKE peer to an IPsec VPN session, perform the following steps.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    crypto isakmp peer {ip-address ip-address}

4.    description


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
crypto isakmp peer {ip-address ip-address}


Example:

Router (config)# crypto isakmp peer address 10.2.2.9

 

Enables an IPsec peer for IKE querying of authentication, authorization, and accounting (AAA) for tunnel attributes in aggressive mode and enters ISAKMP peer configuration mode.

 
Step 4
description


Example:

Router (config-isakmp-peer)# description connection from site A

 

Adds a description for an IKE peer.

 

Verifying Peer Descriptions

To verify peer descriptions, use the show crypto isakmp peer command.

SUMMARY STEPS

1.    enable

2.    show crypto isakmp peer


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
show crypto isakmp peer


Example:

Router# show crypto isakmp peer

 

Displays peer descriptions.

 

Examples

The following output example verifies that the description "connection from site A" has been added for IKE peer 10.2.2.9: 

Router# show crypto isakmp peer
Peer: 10.2.2.9 Port: 500
 Description: connection from site A
  flags: PEER_POLICY

When the peer at address 10.2.2.9 connects and the session comes up, the syslog status will be shown as follows: 

%CRYPTO-5-SESSION_STATUS: Crypto tunnel is UP. Peer 10.2.2.9:500 Description: connection from site A Id: ezvpn

The following output example verifies that the description "connection from site A" has been added for IKE peer 10.2.2.9: 

Router# show crypto isakmp peer
Peer: 10.2.2.9 Port: 500
 Description: connection from site A
  flags: PEER_POLICY

When the peer at address 10.2.2.9 connects and the session comes up, the syslog status will be shown as follows: 

%CRYPTO-5-SESSION_STATUS: Crypto tunnel is UP. Peer 10.2.2.9:500 Description: connection from site A Id: ezvpn

Clearing a Crypto Session

To clear a crypto session, use the clear crypto session command from the router command line. No configuration statements are required in the configuration file to use this command.

SUMMARY STEPS

1.    enable

2.    clear crypto session


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
clear crypto session


Example:

Router# clear crypto session

 

Deletes crypto sessions (IPSec and IKE SAs).

 

Configuration Examples for IP Security VPN Monitoring

show crypto session Command Output Examples

The following is sample output for the show crypto session output without the detail keyword:

Router# show crypto session
Crypto session current status
Interface: FastEthernet0/1
Session status: UP-ACTIVE
Peer: 172.0.0.2/500
   IKE SA: local 172.0.0.1/500 remote 172.0.0.2/500 Active
   IPSEC FLOW: permit ip 10.10.10.0/255.255.255.0 10.30.30.0/255.255.255.0
         Active SAs: 2, origin: crypto map

The following is sample output using the show crypto session command and the detail keyword:

Router# show crypto session detail
Interface: Tunnel0
Session status: UP-ACTIVE
Peer: 10.1.1.3 port 500 fvrf: (none) ivrf: (none)
      Desc: this is my peer at 10.1.1.3:500 Green
      Phase1_id: 10.1.1.3
  IKE SA: local 10.1.1.4/500 remote 10.1.1.3/500 Active
          Capabilities:(none) connid:3 lifetime:22:03:24
  IPSEC FLOW: permit 47 host 10.1.1.4 host 10.1.1.3
        Active SAs: 0, origin: crypto map
        Inbound:  #pkts dec'ed 0 drop 0 life (KB/Sec) 0/0
        Outbound: #pkts enc'ed 0 drop 0 life (KB/Sec) 0/0
  IPSEC FLOW: permit ip host 10.1.1.4 host 10.1.1.3
        Active SAs: 4, origin: crypto map
        Inbound:  #pkts dec'ed 4 drop 0 life (KB/Sec) 4605665/2949
        Outbound: #pkts enc'ed 4 drop 1 life (KB/Sec) 4605665/2949

Additional References

The following sections provide references related to IP Security VPN Monitoring.

Related Documents

Related Topic

Document Title

IP security, encryption, and IKE

  • Configuring Internet Key Exchange for IPsec VPNs
  • Configuring Security for VPNs with IPsec

Security commands

Cisco IOS Security Command Reference

Standards

Standards

Title

No new or modified standards are supported by this feature, and support for exiting standards has not been modified by this feature.

--

MIBs

MIBs

MIBs Link

No new or modified MIBs are supported by this feature, and support for exiting MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS XE software releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFCs

Title

No new or modified RFCs are supported by this feature, and support for exiting RFCs has not been modified by this feature.

--

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport

Feature Information for IP Security VPN Monitoring

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 1 Feature Information for IP Security VPN Monitoring

Feature Name

Releases

Feature Information

IP Security VPN Monitoring

Cisco IOS XE Release 2.1

The IP Security VPN Monitoring feature provides VPN session monitoring enhancements that will allow you to troubleshoot the VPN and monitor the end-user interface. Session monitoring enhancements include the following:

  • Ability to specify an IKE peer description in the configuration file
  • Summary listing of crypto session status
  • Syslog notification for crypto session up or down status

Ability to clear both IKE and IPsec SAs using one CLI

  • The following commands were introduced or modified: clear crypto session, description (isakmp peer), show crypto isakmp peer, show crypto session.

Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at 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. (1005R)

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.

© 2011 Cisco Systems, Inc. All rights reserved.