SafeNet IPsec VPN Client Support

Last Updated: September 13, 2011

The SafeNet IPsec VPN Client Support feature allows you to limit the scope of an Internet Security Association and Key Management Protocol (ISAKMP) profile or ISAKMP keyring configuration to a local termination address or interface. The benefit of this feature is that different customers can use the same peer identities and ISAKMP keys by using different local termination addresses.

History for the SafeNet IPsec VPN Client Support Feature

Release

Modification

12.3(14)T

This feature was introduced.

12.2(18)SXE

This feature was integrated into Cisco IOS Release 12.2(18)SXE.

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Prerequisites for SafeNet IPsec VPN Client Support

  • You must understand how to configure ISAKMP profiles and ISAKMP keyrings.

Restrictions for SafeNet IPsec VPN Client Support

  • The local address option works only for the primary address of an interface.
  • If an IP address is provided, the administrator has to ensure that the connection of the peer terminates to the address that is provided.
  • If the IP address does not exist on the device, or if the interface does not have an IP address, the ISAKMP profile or ISAKMP keyring will be effectively disabled.

Information About SafeNet IPsec VPN Client Support

ISAKMP Profile and ISAKMP Keyring Configurations Background

Prior to Cisco IOS Release 12.3(14)T, ISAKMP-profile and ISAKMP-keyring configurations could be only global, meaning that the scope of these configurations could not be limited by any locally defined parameters (VRF instances were an exception). For example, if an ISAKMP keyring contained a preshared key for address 10.11.12.13, the same key would be used if the peer had the address 10.11.12.13, irrespective of the interface or local address to which the peer was connected. There are situations, however, in which users prefer that associate keyrings be bound not only with virtual route forwarding (VRF) instances but also to a particular interface. For example, if instead of VRF instances, there are virtual LANS, and the Internet Key Exchange (IKE) is negotiated with a group of peers using one fixed virtual LAN (VLAN) interface. Such a group of peers uses a single preshared key, so if keyrings could be bound to an interface, it would be easy to define a wildcard key without risking that the keys would also be used for other customers.

Sometimes the identities of the peer are not in the control of the administrator, and even if the same peer negotiates for different customers, the local termination address is the only way to distinguish the peer. After such a distinction is made, if the traffic is sent to different VRF instances, configuring an ISAKMP profile is the only way to distinguish the peer. Unfortunately, when the peer uses an identical identity for all such situations, the ISAKMP profile cannot distinguish among the negotiations. For such scenarios, it would be beneficial to bind ISAKMP profiles to a local termination address. If a local termination address could be assigned, identical identities from the peer would not be a problem.

Local Termination Address or Interface

Effective with Cisco IOS Release 12.3(14)T, the SafeNet IPsec VPN Client Support feature allows you to limit the scope of ISAKMP profiles and ISAKMP keyrings to a local termination address or interface.

Benefit of SafeNet IPsec VPN Client Support

The benefit of this feature is that different customers can use the same peer identities and ISAKMP keys by using different local termination addresses.

How to Configure SafeNet IPsec VPN Client Support

This section contains the following procedures. The first two configurations are independent of each other.

Limiting an ISAKMP Profile to a Local Termination Address or Interface

To configure an ISAKMP profile and limit it to a local termination address or interface, perform the following steps.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    crypto isakmp profile profile-name

4.    keyring keyring-name

5.    match identity address address

6.    local-address {interface-name | ip-address [vrf-tag ]}


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 profile profile-name


Example:

Router (config)# crypto isakmp profile profile1

 

Defines an ISAKMP profile and enters ISAKMP profile configuration mode.

 
Step 4
keyring keyring-name


Example:

Router (conf-isa-profile)# keyring keyring1

 

(Optional) Configures a keyring with an ISAKMP profile.

  • A keyring is not needed inside an ISAKMP profile for local termination to work. Local termination works even if Rivest, Shamir, and Adelman (RSA) certificates are used.
 
Step 5
match identity address address


Example:

Router (conf-isa-profile)# match identity address 10.0.0.0 255.0.0.0

 

Matches an identity from a peer in an ISAKMP profile.

 
Step 6
local-address {interface-name | ip-address [vrf-tag ]}


Example:

Router (conf-isa-profile)# local-address serial2/0

 

Limits the scope of an ISAKMP profile or an ISAKMP keyring configuration to a local termination address or interface.

 

Limiting a Keyring to a Local Termination Address or Interface

To configure an ISAKMP keyring and limit its scope to a local termination address or interface, perform the following steps.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    crypto keyring keyring-name

4.    local-address {interface-name |ip-address[vrf-tag ]}

5.    pre-shared-key address address


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 keyring keyring-name


Example:

Router (config)# crypto keyring keyring1

 

Defines a crypto keyring to be used during IKE authentication and enters keyring configuration mode.

 
Step 4
local-address {interface-name |ip-address[vrf-tag ]}


Example:

Router (conf-keyring)# local-address serial2/0

 

Limits the scope of an ISAKMP profile or an ISAKMP keyring configuration to a local termination address or interface.

 
Step 5
pre-shared-key address address


Example:

Router (conf-keyring)# pre-shared-key address 10.0.0.1

 

Defines a preshared key to be used for IKE authentication.

 

Monitoring and Maintaining SafeNet IPsec VPN Client Support

The following debug and show commands may be used to monitor and maintain the configuration in which you limited the scope of an ISAKMP profile or ISAKMP keyring to a local termination address or interface.

SUMMARY STEPS

1.    enable

2.    debug crypto isakmp

3.    show crypto isakmp profile


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router> enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
debug crypto isakmp


Example:

Router# debug crypto isakmp

 

Displays messages about IKE events.

 
Step 3
show crypto isakmp profile


Example:

Router# show crypto isakmp profile

 

Lists all the ISAKMP profiles that are defined on a router.

 

Examples

debug crypto isakmp Command Output for an ISAKMP Keyring That IsBound to Local Termination Addresses Example

You have an ISAKMP configuration as follows (the address of serial2/0 is 10.0.0.1, and the address of serial2/1 is 10.0.0.2),

crypto keyring keyring1
! Scope of the keyring is limited to interface serial2/0.
  local-address serial2/0
  ! The following is the key string used by the peer.
  pre-shared-key address 10.0.0.3 key somerandomkeystring
crypto keyring keyring2
  local-address serial2/1
  ! The following is the keystring used by the peer coming into serial2/1.
   pre-shared-key address 10.0.0.3 key someotherkeystring

and if the connection is coming into serial2/0, keyring1 is chosen as the source of the preshared key (and keyring2 is ignored because it is bound to serial2/1), you would see the following output:

Router# debug crypto isakmp
*Feb 11 15:01:29.595: ISAKMP:(0:0:N/A:0):Keyring keyring2 is bound to
  10.0.0.0, skipping
*Feb 11 15:01:29.595: ISAKMP:(0:0:N/A:0):Looking for a matching key for
  10.0.0.3 in keyring1
*Feb 11 15:01:29.595: ISAKMP:(0:0:N/A:0): : success
*Feb 11 15:01:29.595: ISAKMP:(0:0:N/A:0):found peer pre-shared key
  matching 10.0.0.3
*Feb 11 15:01:29.595: ISAKMP:(0:0:N/A:0): local preshared key found
debug crypto isakmp Command Output for an ISAKMP ProfileThat Is Boundto a Local Termination Address Example

If you have the following configuration,

crypto isakmp profile profile1
  keyring keyring1
  match identity address 10.0.0.0 255.0.0.0
  local-address serial2/0
crypto isakmp profile profile2
  keyring keyring1
  keyring keyring2
  self-identity fqdn
  match identity address 10.0.0.1 255.255.255.255
  local-address serial2/1

and the connection is coming through the local terminal address serial2/0, you will see the following output:

Router# debug crypto isakmp
*Feb 11 15:01:29.935: ISAKMP:(0:0:N/A:0):
Profile profile2 bound to 10.0.0.0 skipped
*Feb 11 15:01:29.935: ISAKMP:(0:1:SW:1):: peer matches profile1 profile
show crypto isakmp profile Command Output Example

The following is an example of typical show command output for an ISAKMP profile that is bound to serial2/0:

Router# show crypto isakmp profile
ISAKMP PROFILE profile1
  Identities matched are:
    ip-address 10.0.0.0 255.0.0.0
  Certificate maps matched are:
  keyring(s): keyring1
  trustpoint(s): <all>
  Interface binding: serial2/0 (10.20.0.1:global)

Troubleshooting SafeNet IPsec VPN Client Support

If an ISAKMP profile or ISAKMP keyring fails to be selected, you should double-check the local-address binding in the ISAKMP profile or ISAKMP keyring configuration and follow the output of the IKE debugs to determine whether the peer is correctly terminating on the address. You may remove the local-address binding (to make the scope of the profile or keyring global) and check to determine whether the profile or keyring is selected to confirm the situation.

Configuration Examples for SafeNet IPsec VPN Client Support

This section contains the following configuration, debug command, and show command examples.

ISAKMP Profile Bound to a Local Interface Example

The following example shows that the ISAKMP profile is bound to a local interface:

crypto isakmp profile profile1
  keyring keyring1
  match identity address 10.0.0.0 255.0.0.0

local-address serial2/0

ISAKMP Keyring Bound to a Local Interface Example

The following example shows that the ISAKMP keyring is bound only to interface serial2/0:

crypto keyring
  local-address serial2/0 

pre-shared-key address 10.0.0.1

ISAKMP Keyring Bound to a Local IP Address Example

The following example shows that the ISAKMP keyring is bound only to IP address 10.0.0.2:

crypto keyring keyring1
  local-address 10.0.0.2

pre-shared-key address 10.0.0.2 key

ISAKMP Keyring Bound to an IP Address and Limited to a VRF Example

The following example shows that an ISAKMP keyring is bound to IP address 10.34.35.36 and that the scope is limited to VRF examplevrf1:

ip vrf examplevrf1
  rd 12:3456
crypto keyring ring1
  local-address 10.34.35.36 examplevrf1
interface ethernet2/0
  ip vrf forwarding examplevrf1
  ip address 10.34.35.36 255.255.0.0

Additional References

The following sections provide references related to SafeNet IPsec VPN Client Support.

Related DocumentsStandards

Related Topic

Document Title

Configuring ISAKMP profiles and ISAKMP keyrings

VRF-Aware IPsec

Security commands

Cisco IOS Security Command Reference

Standard

Title

No new or modified standards are supported by this feature.

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MIBs

MIB

MIBs Link

No new or modified MIBs are supported by this feature.

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

RFCs

RFC

Title

No new or modified RFCs are supported by this feature.

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