Cisco IOS Security Configuration Guide: Secure Connectivity, Release 12.4 - Reverse Route Injection [Cisco IOS Software Releases 12.4 Mainline]

Table Of Contents

Reverse Route Injection

Contents

Prerequisites for Reverse Route Injection

Restrictions for Reverse Route Injection

Information About Reverse Route Injection

Reverse Route Injection

Enhancements to Reverse Route Injection in Cisco IOS Release 12.4(15)T

RRI Distance Metric

Gateway Option

Support for RRI on IPsec Profiles

Tag Option Configuration Changes

show crypto route Command

How to Configure Reverse Route Injection

Configuring RRI on Crypto Maps for Cisco IOS Releases Prior to 12.4(15)T

Configuring RRI Under a Static Crypto Map

Configuring RRI Under a Dynamic Map Template

Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T

Configuring RRI with Enhancements Under a Static Crypto Map

Configuring RRI with Enhancements Under a Dynamic Map Template

Configuring a RRI Distance Metric Under an IPsec Profile

Verifying Routes That Are Created Through IPsec via RRI or Easy VPN VTIs

Troubleshooting Tips

Configuration Examples for Reverse Route Injection

Configuring RRI Prior to Cisco IOS Release 12.3(14)T: Examples

Configuring RRI When Crypto ACLs Exist: Example

Configuring RRI When Two Routes Are Created, One for the Remote Endpoint and One for Route Recursion: Example

Configuring RRI with Enhancements Added in Cisco IOS Release 12.3(14)T: Examples

Configuring RRI When Crypto ACLs Exist: Example

Configuring RRI with Route Tags: Example

Configuring RRI for One Route to the Remote Proxy via a User-Defined Next Hop: Example

Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T: Examples

Configuring a RRI Distance Metric Under a Crypto Map: Example

Configuring RRI with Route Tags: Example

debug and show Command Output for a RRI Distance Metric Configuration Under a Crypto Map: Example

Configuring a RRI Distance Metric for a VTI: Example

debug and show Command Output for a RRI Metric Configuration Having a VTI: Example

show crypto route Command Output: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

Feature Information for Reverse Route Injection

Reverse Route Injection

First Published: August 16, 2001

Last Updated: November 5, 2007

Reverse route injection (RRI) is the ability for static routes to be automatically inserted into the routing process for those networks and hosts protected by a remote tunnel endpoint. These protected hosts and networks are known as remote proxy identities.

Each route is created on the basis of the remote proxy network and mask, with the next hop to this network being the remote tunnel endpoint. By using the remote Virtual Private Network (VPN) router as the next hop, the traffic is forced through the crypto process to be encrypted.

Enhancements to the default behavior of RRI, the addition of a route tag value, and enhancements to how RRI is configured were added to the Reverse Route Injection feature in Cisco IOS Release 12.3(14)T.

An enhancement was added in Cisco IOS Release 12.4(15)T that allows a distance metric to be set for routes that are created by a VPN process so that the dynamically learned route on a router can take precedence over a locally configured static route.

Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for Reverse Route Injection" section.

Finding Support Information for Platforms and Cisco IOS Catalyst OS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp. An account on Cisco.com is not required.

Contents

•Prerequisites for Reverse Route Injection

•Restrictions for Reverse Route Injection

•Information About Reverse Route Injection

•How to Configure Reverse Route Injection

•Configuration Examples for Reverse Route Injection

•Additional References

•Command Reference

•Feature Information for Reverse Route Injection, page 26

Prerequisites for Reverse Route Injection

•IP routing should be enabled and static routes should be redistributed if dynamic routing protocols are to be used to propagate RRI-generated static routes.

Restrictions for Reverse Route Injection

•If RRI is applied to a crypto map, that map must be unique to one interface on the router. In other words, the same crypto map cannot be applied to multiple interfaces. If more than one crypto map is applied to multiple interfaces, routes may not be cleaned up correctly. If multiple interfaces require a crypto map, each must use a uniquely defined map. This restriction applies only to RRI before Cisco IOS Release 12.3(14)T.

•For static crypto maps, routes are always present if RRI is configured on an applied crypto map. In Cisco IOS Release 12.3(14)T, the default behavior—of routes always being present for a static map—will not apply unless the static keyword is added to the reverse-route command.

Information About Reverse Route Injection

To configure the Reverse Route Injection enhancements, you should understand the following concepts:

•Reverse Route Injection

•Enhancements to Reverse Route Injection in Cisco IOS Release 12.4(15)T

Reverse Route Injection

RRI is the ability for static routes to be automatically inserted into the routing process for those networks and hosts that are protected by a remote tunnel endpoint. These protected hosts and networks are known as remote proxy identities.

Each route is created on the basis of the remote proxy network and mask, with the next hop to this network being the remote tunnel endpoint. By using the remote VPN router as the next hop, the traffic is forced through the crypto process to be encrypted.

After the static route is created on the VPN router, this information is propagated to upstream devices, allowing them to determine the appropriate VPN router to which to send returning traffic in order to maintain IPsec state flows. Being able to determine the appropriate VPN router is particularly useful if multiple VPN routers are used at a site to provide load balancing or failover or if the remote VPN devices are not accessible via a default route. Routes are created in either the global routing table or the appropriate virtual route forwarding (VRF) table.

RRI is applied on a per-crypto map basis, whether this is via a static crypto map or a dynamic crypto map template. The default behavior for the two map types is as follows:

•In the case of a dynamic crypto map, routes are created upon the successful establishment of IPsec security associations (SAs) for those remote proxies. The next hop back to those remote proxies is via the remote VPN router whose address is learned and applied during the creation of the dynamic crypto map template. The routes are deleted after the SAs are deleted. In Cisco IOS Release 12.3(14)T, the creation of routes on the basis of IPsec source proxies on static crypto maps was added. This behavior became the default behavior on static maps and overrode the creation of routes on the basis of crypto ACLs (see the next bullet).

•For static crypto maps, routes are created on the basis of the destination information defined in the crypto access list. The next hop is taken from the first set peer statement that is attached to the crypto map. If at any time, RRI, the peer, or the access list is removed from the crypto map, routes will be deleted. This behavior changes with the addition of the RRI enhancements, as explained in the sections below.

Enhancements to Reverse Route Injection in Cisco IOS Release 12.4(15)T

The following enhancements have been added to the Reverse Route Injection feature in Cisco IOS Release 12.4(15)T:

•RRI Distance Metric

•Gateway Option

•Support for RRI on IPsec Profiles

•Tag Option Configuration Changes

•show crypto route Command

RRI Distance Metric

In general, a static route is created having an administrative distance of 1, which means that static routes always have precedence in the routing table. In some scenarios, however, it is required that dynamically learned routes take precedence over static routes, with the static route being used in the absence of a dynamically learned route. The addition of the set reverse-route distance command under either a crypto map or IPsec profile allows you to specify a different distance metric for VPN-created routes so that those routes will be in effect only if a dynamic or more favored route becomes unavailable.

Gateway Option

This RRI gateway option is relevant to the crypto map only.

This option allows you to configure unique next hops or gateways for remote tunnel endpoints. The option is identical to the way the reverse-route remote-peer {ip-address} command worked prior to Cisco IOS Release 12.3(14)T in that two routes are created for each VPN tunnel. The first route is to the destination-protected subnet via the remote tunnel endpoint. The second route specifies the next hop to be taken to reach this tunnel endpoint. This RRI gateway option allows specific default paths to be specified for specific groups of VPN connections on platforms that support recursive route lookups.

Note In 12.4(15)T and later releases, the gateway keyword option replaces the reverse-route remote-peer command (with no ip-address). Due to changes to Cisco Express Forwarding (CEF), an interface as a next-hop cannot be used without also adding a next-hop IP address.

Support for RRI on IPsec Profiles

Previously RRI was available for crypto map configurations only. Cisco IOS Release 12.4(15)T introduces support for relevant RRI options on IPsec profiles that are predominantly used for virtual tunnel interfaces. On tunnel interfaces, only the distance metric and tag options are useful with the generic RRI capability.

Note It is not necessary to specifically enable RRI on dynamic virtual interfaces for Easy VPN clients. Route support is enabled by default. It is necessary to specify tag or distance metric values if these are required.

Tag Option Configuration Changes

The tag option was introduced in 12.3(14)T for crypto maps. This option is now supported with IPsec profiles under the set reverse-route tag command syntax. The set reverse-route tag command is also available under the crypto map for uniformity although the legacy reverse-route tag command is no longer supported.

show crypto route Command

The show crypto route command displays routes that are created through IPsec via RRI or Easy VPN virtual tunnel interfaces (VTIs). The routes are displayed in one table. To see sample output for the show crypto route command, see the section "show crypto route Command Output: Example."

How to Configure Reverse Route Injection

The following sections show how to configure reverse route injection for Cisco IOS software before Release 12.4(15)T and for Release 12.4(15)T.

•Configuring RRI on Crypto Maps for Cisco IOS Releases Prior to 12.4(15)T

•Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T

Configuring RRI on Crypto Maps for Cisco IOS Releases Prior to 12.4(15)T

This section includes the following tasks:

•Configuring RRI Under a Static Crypto Map

•Configuring RRI Under a Dynamic Map Template

Configuring RRI Under a Static Crypto Map

To configure RRI under a static crypto map for Cisco IOS software prior to Release 12.4(15)T, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto map {map-name} {seq-name} ipsec-isakmp

4. reverse-route [static | tag tag-id [static] | remote-peer [static] | remote-peer ip-address [static]]

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 map {map-name} {seq-name} ipsec-isakmp
Example:

Router (config)# crypto map mymap 1 ipsec-isakmp

Creates or modifies a crypto map entry and enters crypto map configuration mode.

Step 4

reverse-route [static | tag tag-id [static] | remote-peer [static] | remote-peer ip-address [static]]
Example:

Router (config-crypto-map)# reverse-route remote peer 10.1.1.1

Creates source proxy information for a crypto map entry.

Configuring RRI Under a Dynamic Map Template

To configure RRI under a dynamic map template for Cisco IOS software prior to Release 12.4(15)T, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto dynamic-map dynamic-map-name dynamic-seq-name

4. reverse-route [static | tag tag-id [static] | remote-peer [static] | remote-peer ip-address [static]]

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 dynamic-map dynamic-map-name dynamic-seq-name
Example:

Router (config)# crypto dynamic-map mymap 1

Creates a dynamic crypto map entry and enters the crypto map configuration command mode.

Step 4

reverse-route [static | tag tag-id [static] | remote-peer [static] | remote-peer ip-address [static]]
Example:

Router (config-crypto-map)# reverse-route remote peer 10.1.1.1

Creates source proxy information for a crypto map entry.

Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T

The following sections show how to configure RRI with the enhancements that were added in Cisco IOS Release 12.4(15)T:

•Configuring RRI with Enhancements Under a Static Crypto Map

•Configuring RRI with Enhancements Under a Dynamic Map Template

•Configuring a RRI Distance Metric Under an IPsec Profile

•Verifying Routes That Are Created Through IPsec via RRI or Easy VPN VTIs

Configuring RRI with Enhancements Under a Static Crypto Map

To configure RRI with enhancements under a static crypto map (for Cisco IOS Release 12.4(15)T and later releases), perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto map map-name seq-name ipsec-isakmp

4. reverse-route [static | remote-peer ip-address [gateway ] [static]]

5. set reverse-route [distance number | tag tag-id]

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 map map-name seq-name ipsec-isakmp
Example:

Router (config)# crypto map mymap 1 ipsec-isakmp

Creates or modifies a crypto map entry and enters crypto map configuration mode.

Step 4

reverse-route [static | remote-peer ip-address [gateway] [static]]
Example:

Router (config-crypto-map)# reverse-route

Creates source proxy information for a crypto map entry.

Note The gateway keyword can be added to enable the dual route functionality for default gateway support.

Step 5

set reverse-route [distance number | tag tag-id]
Example:

Router (config-crypto-map)# set reverse-route distance 20

Specifies a distance metric to be used or a tag value to be associated with these routes.

Configuring RRI with Enhancements Under a Dynamic Map Template

To configure RRI with enhancements under a dynamic map template (for Cisco IOS Release 12.4(15)T and later releases), perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto dynamic-map dynamic-map-name dynamic-seq-name

4. reverse-route [static | remote-peer ip-address [gateway ] [static]]

5. set reverse-route [distance number | tag tag-id]

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 dynamic-map dynamic-map-name dynamic-seq-name
Example:

Router (config)# crypto dynamic-map mymap 1

Creates a dynamic crypto map entry and enters the crypto map configuration command mode.

Step 4

reverse-route [static | remote-peer ip-address [gateway] [static]]
Example:

Router (config-crypto-map)# reverse-route remote peer 10.1.1.1 gateway

Creates source proxy information for a crypto map entry.

Step 5

set reverse-route [distance number | tag tag-id]
Example:

Router (config-crypto-map)# set reverse-route distance 20

Specifies a distance metric to be used or a tag value to be associated with these routes.

Configuring a RRI Distance Metric Under an IPsec Profile

To configure a RRI distance metric under an IPsec profile for Cisco IOS Release 12.4(15)T and later releases, perform the following steps:

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto ipsec profile name

4. set reverse-route [distance number | tag tag-id]

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 ipsec profile name
Example:

Router (config)# crypto ipsec profile myprofile

Creates or modifies an IPsec profile and enters IPsec profile configuration mode.

Step 4

set reverse-route [distance number | tag tag-id]
Example:

Router (config-crypto-profile)# set reverse-route distance 20

Defines a distance metric for each static route or tags a reverse route injection- (RRI-) created route.

•distance—Defines a distance metric for each static route.

•tag—Sets a tag value that can be used as a "match" value for controlling distribution using route maps.

Verifying Routes That Are Created Through IPsec via RRI or Easy VPN VTIs

To display routes that are created through IPsec via RRI or Easy VPN VTIs, perform the following steps.

SUMMARY STEPS

1. enable

2. show crypto route

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 route
Example:

Router# show crypto route

Displays routes that are created through IPsec via RRI or Easy VPN VTIs.

Troubleshooting Tips

To observe the behavior of RRI and its relationship to the creation and deletion of an IPsec SA, you can use the debug crypto ipsec command (see the Cisco IOS Debug Command Reference.

Configuration Examples for Reverse Route Injection

This section contains the following sections:

•Configuring RRI Prior to Cisco IOS Release 12.3(14)T: Examples

•Configuring RRI with Enhancements Added in Cisco IOS Release 12.3(14)T: Examples

•Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T: Examples

Configuring RRI Prior to Cisco IOS Release 12.3(14)T: Examples

The following are examples of RRI configurations and output before Cisco IOS Release 12.3(14))T:

•Configuring RRI When Crypto ACLs Exist: Example

•Configuring RRI When Two Routes Are Created, One for the Remote Endpoint and One for Route Recursion: Example

Configuring RRI When Crypto ACLs Exist: Example

The following example shows that all remote VPN gateways connect to the router via 192.168.0.3. RRI is added on the static crypto map, which creates routes on the basis of the source network and source netmask that are defined in the crypto access control list (ACL):
crypto map mymap 1 ipsec-isakmp
 set peer 10.1.1.1
 reverse-route
 set transform-set esp-3des-sha
 match address 102
Interface FastEthernet 0/0
 ip address 192.168.0.2 255.255.255.0
 standby name group1
 standby ip 192.168.0.3
 crypto map mymap redundancy group1
access-list 102 permit ip 192.168.1.0 0.0.0.255 10.0.0.0 0.0.255.255
In Cisco IOS Release 12.3(14)T and later releases, for the static map to retain this same behavior of creating routes on the basis of crypto ACL content, the static keyword is required, that is, reverse-route static.

Note The reverse-route command in this situation creates routes that are analogous to the following static route command-line interface (CLI) commands (ip route):

Remote Tunnel Endpoint
ip route 10.1.1.1 255.255.255.255 192.168.1.1
VPNSM

ip route 10.1.1.1 255.255.255.255 vlan0.1

Configuring RRI When Two Routes Are Created, One for the Remote Endpoint and One for Route Recursion: Example

In the following example, two routes are created, one for the remote endpoint and one for route recursion to the remote endpoint via the interface on which the crypto map is configured:
reverse-route remote-peer
Configuring RRI with Enhancements Added in Cisco IOS Release 12.3(14)T: Examples

The following are examples of configurations and output for RRI enhancements that were added in Cisco IOS Release 12.3(14)T.

•Configuring RRI When Crypto ACLs Exist: Example

•Configuring RRI with Route Tags: Example

•Configuring RRI for One Route to the Remote Proxy via a User-Defined Next Hop: Example

Configuring RRI When Crypto ACLs Exist: Example

The following example shows that RRI has been configured for a situation in which there are existing ACLs:
crypto map mymap 1 ipsec-isakmp
   set peer 172.17.11.1
   reverse-route static
   set transform-set esp-3des-sha
   match address 101
access-list 101 permit ip 192.168.1.0 0.0.0.255 172.17.11.0 0.0.0.255
Configuring RRI with Route Tags: Example

The following example shows how RRI-created routes can be tagged with a tag number and then used by a routing process to redistribute those tagged routes via a route map:
crypto dynamic-map ospf-clients 1
 reverse-route tag 5
router ospf 109
 redistribute rip route-map rip-to-ospf
route-map rip-to-ospf permit
 match tag 5
 set metric 5
 set metric-type type1
Router# show ip ospf topology
P 10.81.7.48/29, 1 successors, FD is 2588160, tag is 5
     via 192.168.82.25 (2588160/2585600), FastEthernet0/1
Configuring RRI for One Route to the Remote Proxy via a User-Defined Next Hop: Example

Note This option is applicable only to crypto maps.

The preceding example shows that one route has been created to the remote proxy via a user-defined next hop. This next hop should not require a recursive route lookup unless it will recurse to a default route.
reverse-route remote-peer 10.4.4.4
The preceding example yields the following prior to Cisco IOS Release 12.3(14)T:
10.0.0.0/24 via 10.1.1.1 (in the VRF table if VRFs are configured)
10.1.1.1/32 via 10.4.4.4 (in the global route table)
And this result occurs with RRI enhancements:
10.0.0.0/24 via 10.4.4.4 (in the VRF table if VRFs are configured, otherwise in the global 
table)
Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T: Examples

The following are examples of configurations and output for RRI enhancements that were added in Cisco IOS Release 12.4(15)T.

•Configuring a RRI Distance Metric Under a Crypto Map: Example

•Configuring RRI with Route Tags: Example

•debug and show Command Output for a RRI Distance Metric Configuration Under a Crypto Map: Example

•Configuring a RRI Distance Metric for a VTI: Example

•debug and show Command Output for a RRI Metric Configuration Having a VTI: Example

•show crypto route Command Output: Example

Configuring a RRI Distance Metric Under a Crypto Map: Example

The following configuration shows a server and client configuration for which a RRI distance metric has been set under a crypto map:

Server
crypto dynamic-map mymap
 set security-association lifetime seconds 300
 set transform-set 3dessha 
 set isakmp-profile profile1
 set reverse-route distance 20
 reverse-route
Client
crypto ipsec client ezvpn ez
 connect auto
 group cisco key cisco
 mode client
 peer 10.0.0.119
 username XXX password XXX
 xauth userid mode local
Configuring RRI with Route Tags: Example

The following example shows how RRI-created routes can be tagged with a tag number and then used by a routing process to redistribute those tagged routes via a route map:
crypto dynamic-map ospf-clients 1
 set reverse-route tag 5
router ospf 109
 redistribute rip route-map rip-to-ospf
route-map rip-to-ospf permit
 match tag 5
 set metric 5
 set metric-type type1
Router# show ip ospf topology
P 10.81.7.48/29, 1 successors, FD is 2588160, tag is 5
  via 192.168.82.25 (2588160/2585600), FastEthernet0/1
debug and show Command Output for a RRI Distance Metric Configuration Under a Crypto Map: Example

The following are debug and show command output for a RRI distance metric configuration under a crypto map on a server:
Router# debug crypto ipsec
00:23:37: IPSEC(validate_proposal_request): proposal part #1,
  (key eng. msg.) INBOUND local= 10.0.0.119, remote= 10.0.0.14, 
    local_proxy= 0.0.0.0/0.0.0.0/0/0 (type=4), 
    remote_proxy= 192.168.6.1/255.255.255.255/0/0 (type=1),
    protocol= ESP, transform= esp-3des esp-sha-hmac  (Tunnel), 
    lifedur= 0s and 0kb, 
    spi= 0x0(0), conn_id= 0, keysize= 0, flags= 0x0
00:23:37: IPSEC(key_engine): got a queue event with 1 KMI message(s)
00:23:37: IPSEC(rte_mgr): VPN Route Event create routes for peer or rekeying for
 10.0.0.128
00:23:37: IPSEC(rte_mgr): VPN Route Refcount 1 FastEthernet0/0
00:23:37: IPSEC(rte_mgr): VPN Route Added 192.168.6.1 255.255.255.255 via 10.0.0.14 in IP 
DEFAULT TABLE with tag 0 distance 20
00:23:37: IPSEC(policy_db_add_ident): src 0.0.0.0, dest 192.168.6.1, dest_port 0
Router# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is 10.0.0.14 to network 0.0.0.0
C    192.200.200.0/24 is directly connected, Loopback0
     10.20.20.20/24 is subnetted, 1 subnets
C       10.30.30.30 is directly connected, Loopback4
C    192.168.5.0/24 is directly connected, Loopback3
     10.20.20.20/24 is subnetted, 2 subnets
S       10.3.1.0 [1/0] via 10.0.0.113
C       10.20.20.20 is directly connected, FastEthernet0/0
     192.168.6.0/32 is subnetted, 1 subnets
S       192.168.6.1 [20/0] via 10.0.0.14
C    192.168.3.0/24 is directly connected, Loopback2
     10.15.0.0/24 is subnetted, 1 subnets
C       10.15.0.0 is directly connected, Loopback6
S*   0.0.0.0/0 [1/0] via 10.0.0.14
Configuring a RRI Distance Metric for a VTI: Example

The following configuration shows a server and client configuration in which a RRI distance metric has been set for a VTI:

Server Configuration
crypto isakmp profile profile1
 keyring mykeyring
 match identity group cisco
 client authentication list authenlist
 isakmp authorization list autholist
 client configuration address respond
 virtual-template 1
crypto ipsec profile vi
 set transform-set 3dessha 
 set reverse-route distance 20
 set isakmp-profile profile1
!
interface Virtual-Template1 type tunnel
 ip unnumbered
 tunnel mode ipsec ipv4
 tunnel protection ipsec profile vi
Client Configuration
crypto ipsec client ezvpn ez
 connect auto
 group cisco key cisco
 mode client
 peer 10.0.0.119
 username XXX password XXX
 virtual-interface 1
debug and show Command Output for a RRI Metric Configuration Having a VTI: Example

The following are debug and show command output for a RRI metric configuration for a VTI on a server:
Router# debug crypto ipsec
00:47:56: IPSEC(key_engine): got a queue event with 1 KMI message(s)
00:47:56: Crypto mapdb : proxy_match
        src addr     : 0.0.0.0
        dst addr     : 192.168.6.1
        protocol     : 0
        src port     : 0
        dst port     : 0
00:47:56: IPSEC(crypto_ipsec_sa_find_ident_head): reconnecting with the same pro
xies and peer 10.0.0.14
00:47:56: IPSEC(rte_mgr): VPN Route Event create routes for peer or rekeying for
 10.0.0.14
00:47:56: IPSEC(rte_mgr): VPN Route Refcount 1 Virtual-Access2
00:47:56: IPSEC(rte_mgr): VPN Route Added 192.168.6.1 255.255.255.255 via Virtua
l-Access2 in IP DEFAULT TABLE with tag 0 distance 20
00:47:56: IPSEC(policy_db_add_ident): src 0.0.0.0, dest 192.168.6.1, dest_port 0
00:47:56: IPSEC(create_sa): sa created,
  (sa) sa_dest= 10.0.0.110, sa_proto= 50, 
    sa_spi= 0x19E1175C(434181980), 
    sa_trans= esp-3des esp-sha-hmac , sa_conn_id= 87
00:47:56: IPSEC(create_sa): sa created,
  (sa) sa_dest= 10.0.0.14, sa_proto= 50, 
    sa_spi= 0xADC90C5(182227141), 
    sa_trans= esp-3des esp-sha-hmac , sa_conn_id= 88
00:47:56: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, chang
ed state to up
00:47:56: IPSEC(key_engine): got a queue event with 1 KMI message(s)
00:47:56: IPSEC(key_engine_enable_outbound): rec'd enable notify from ISAKMP
00:47:56: IPSEC(key_engine_enable_outbound): enable SA with spi 182227141/50 
00:47:56: IPSEC(update_current_outbound_sa): updated peer 10.0.0.14 current outb
ound sa to SPI ADC90C5
Router# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
Gateway of last resort is 10.0.0.14 to network 0.0.0.0
C    192.200.200.0/24 is directly connected, Loopback0
     10.20.20.20/24 is subnetted, 1 subnets
C       10.30.30.30 is directly connected, Loopback4
C    192.168.5.0/24 is directly connected, Loopback3
     10.20.20.20/24 is subnetted, 2 subnets
S       10.3.1.0 [1/0] via 10.0.0.113
C       10.20.20.20 is directly connected, FastEthernet0/0
     192.168.6.0/32 is subnetted, 1 subnets
S       192.168.6.1 [20/0] via 0.0.0.0, Virtual-Access2
C    192.168.3.0/24 is directly connected, Loopback2
     10.15.0.0/24 is subnetted, 1 subnets
C       10.15.0.0 is directly connected, Loopback6
S*   0.0.0.0/0 [1/0] via 10.0.0.14
show crypto route Command Output: Example

The following output example displays routes, in one table, that are created through IPsec via RRI or Easy VPN VTIs:
Router# show crypto route
VPN Routing Table: Shows RRI and VTI created routes
Codes: RRI - Reverse-Route, VTI- Virtual Tunnel Interface
        S - Static Map ACLs
Routes created in table GLOBAL DEFAULT
192.168.6.2/255.255.255.255 [0/0] via 10.0.0.133
                                on Virtual-Access3 RRI  
10.1.1.0/255.255.255.0 [10/0] via Virtual-Access2 VTI
192.168.6.1/255.255.255.255 [0/0] via Virtual-Access2 VTI
Additional References

The following sections provide references related to Reverse Route Injection enhancements.

Related Documents

Related Topic

Document Title

Cisco IOS Security commands

Cisco IOS Security Command Reference

Other Cisco IOS commands

Cisco IOS Master Command List

Standards

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—

MIBs

MIBs

MIBs Link

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

RFCs

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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

Command Reference

The following commands are introduced or modified in the feature or features

•reverse-route

•set reverse-route

•show crypto route

For information about these commands, see the Cisco IOS Security Command Reference at

http://www.cisco.com/en/US/docs/ios/security/command/reference/sec_book.html.

For information about all Cisco IOS commands, see the Command Lookup Tool at

http://tools.cisco.com/Support/CLILookup or the Master Command List.

Feature Information for Reverse Route Injection

Table 1 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp. An account on Cisco.com is not required.

Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

Table 1 Feature Information for Reverse Route Injection

Feature Name

Releases

Feature Information

Reverse Route Injection

12.1(9)E

12.2(8)T

12.2(8)YE

Reverse route injection (RRI) is the ability for static routes to be automatically inserted into the routing process for those networks and hosts protected by a remote tunnel endpoint. These protected hosts and networks are known as remote proxy identities.

Each route is created on the basis of the remote proxy network and mask, with the next hop to this network being the remote tunnel endpoint. By using the remote Virtual Private Network (VPN) router as the next hop, the traffic is forced through the crypto process to be encrypted.

The following sections provide information about this feature:

•"Reverse Route Injection" section

The following commands were introduced or modified by this feature: reverse-route.

Reverse Route Remote Peer Options

12.2(13)T

12.2(14)S

An enhancement was added to RRI to allow you to specify an interface or address as the explicit next hop to the remote VPN device. This functionality allows the overriding of a default route to properly direct outgoing encrypted packets.

The following sections provide information about the remote peer options:

•"Enhancements to Reverse Route Injection in Cisco IOS Release 12.4(15)T" section.

Reverse Route Injection Enhancements

12.3(14)T

12.2(33)SRA
12.2(33)SXH

The following enhancements were added to the Reverse Route Injection feature:

•The default behavior of static crypto maps will be the same as that of dynamic crypto maps unless the reverse-route command and static keyword are used.

•A route tag value was added for any routes that are created using RRI.

•RRI can be configured on the same crypto map that is applied to multiple router interfaces.

•RRI configured with the reverse-route remote-peer {ip-address} command, keyword, and argument will create one route instead of two.

The following sections provide information about the Reverse Route Injection enhancements:

•"Reverse Route Injection" section

•"Configuring RRI on Crypto Maps for Cisco IOS Releases Prior to 12.4(15)T" section

•"Configuring RRI with Enhancements Added in Cisco IOS Release 12.4(15)T" section

•"Configuring RRI When Crypto ACLs Exist: Example" section

•"Configuring RRI with Route Tags: Example" section

•"Configuring RRI for One Route to the Remote Proxy via a User-Defined Next Hop: Example" section

The following command was modified by these feature enhancements: reverse-route.

Gateway Option

12.4(15)T

This option allows you to configure unique next hops or gateways for remote tunnel endpoints.

The following section provides information about the Gateway Option:

•"Gateway Option" section

RRI Distance Metric

12.4(15)T

This enhancement allows you to define a metric distance for each static route.

The following sections provide information about the RRI distance metric enhancement.

•"RRI Distance Metric" section

•"Configuring a RRI Distance Metric Under an IPsec Profile" section

•"Configuring a RRI Distance Metric Under a Crypto Map: Example" section

•"debug and show Command Output for a RRI Metric Configuration Having a VTI: Example" section

The following commands were introduced or modified by this feature: reverse-route, set reverse-route.

show crypto route Command

12.4(15)T

This command displays routes that are created through IPsec via RRI or Easy VPN VTIs.

Support for RRI on IPsec Profiles

12.4(15)T

This feature provides support for relevant RRI options on IPsec profiles that are predominantly used by VTIs.

The following section provides information about the Support for RRI on IPsec Profiles feature:

•"Support for RRI on IPsec Profiles" section

Tag Option Configuration Changes

12.4(15)T

The tag option is now supported with IPsec profiles under the set reverse-route tag command.

The following section provides information about this feature enhancement:

•"Tag Option Configuration Changes" section

Reverse Route Injection (RRI)

Cisco IOS XE Release 2.1

This feature was introduced on Cisco ASR 1000 Series Routers.

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