IP Security VPN Monitoring
First Published: November 3, 2003
Last Updated: March 29, 2011
The IP Security VPN Monitoring feature provides the following Virtual Private Network (VPN) session monitoring enhancements to troubleshoot and monitor the end-user interface:
•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 for IP Security VPN Monitoring" section.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Prerequisites for IP Security VPN Monitoring
•Restrictions for IP Security VPN Monitoring
•Information About IPSec VPN Monitoring
•How to Configure IP Security VPN Monitoring
•Configuration Examples for IP Security VPN Monitoring
•Additional References
•Feature Information for IP Security VPN Monitoring
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 k8 or k9 crypto images on your router.
Information About IPSec VPN Monitoring
To troubleshoot the IPSec VPN and monitor the end-user interface, you should understand the following concepts:
•Background: Crypto Sessions
•Per-IKE Peer Description
•Summary Listing of Crypto Session Status
•Syslog Notification for Crypto Session Up or Down Status
•IKE and IPSec Security Exchange Clear Command
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. (Before Cisco IOS Release 12.3(4)T, you could use only the IP address or fully qualified domain name [FQDN] to identify the peer; there was no way to configure a description string.) 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
In previous IOS versions, there was no single command to clear both IKE and IPSec connections (that is, SAs). Instead, you had to use the clear crypto isakmp command to clear IKE and the clear crypto ipsec command to clear IPSec. The new 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
See the following sections for configuration tasks for this feature. Each task in the list is identified as either required or optional.
•Adding the Description of an IKE Peer (optional)
•Verifying Peer Descriptions (optional)
•Clearing a Crypto Session (optional)
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
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
configure terminal
Router# configure terminal |
Enters global configuration mode. |
Step 3 |
crypto isakmp peer {ip-address ip-address}
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
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
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
show crypto isakmp peer
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
Description: connection from site A
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
|
|
|
Step 1 |
enable
Router> enable |
Enables privileged EXEC mode. •Enter your password if prompted. |
Step 2 |
clear crypto session
Router# clear crypto session |
Deletes crypto sessions (IPSec and IKE SAs). |
Configuration Examples for IP Security VPN Monitoring
This section provides the following configuration example:
•show crypto session Command Output: Examples
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
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
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
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
Related Documents
MIBs
|
|
None. |
To locate and download MIBs for selected platforms, Cisco IOS software releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs |
Technical Assistance
|
|
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. |
http://www.cisco.com/cisco/web/support/index.html |
Feature Information for IP Security VPN Monitoring
Table 1 lists the release history for this feature.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 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.
Table 1 Feature Information for IP Security VPN Monitoring
|
|
|
IP Security VPN Monitoring |
12.3(4)T |
The IP Security VPN Monitoring feature provides the following Virtual Private Network (VPN) session monitoring enhancements to troubleshoot and monitor the end-user interface: •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) This feature was introduced in Cisco IOS Release 12.3(4)T. The following commands were introduced or modified: clear crypto session, description (isakmp peer), show crypto isakmp peers, 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.
© 2003-2011 Cisco Systems, Inc. All rights reserved.