IP EIGRP Route Authentication

The IP Enhanced IGRP Route Authentication feature provides MD5 authentication of routing updates from the EIGRP routing protocol. The MD5 keyed digest in each EIGRP packet prevents the introduction of unauthorized or false routing messages from unapproved sources.

Finding Feature Information

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Information About IP EIGRP Route Authentication

EIGRP Route Authentication

EIGRP route authentication provides MD5 authentication of routing updates from the EIGRP routing protocol. The MD5 keyed digest in each EIGRP packet prevents the introduction of unauthorized or false routing messages from unapproved sources.

Each key has its own key identifier (specified with the key number key chain configuration command), which is stored locally. The combination of the key identifier and the interface associated with the message uniquely identifies the authentication algorithm and the MD5 authentication key in use.

You can configure multiple keys with specific lifetimes. Only one authentication packet is sent, regardless of how many valid keys exist. The software examines the key numbers in the order from lowest to highest, and uses the first valid key that it encounters. Note that the device needs to know the time to configure keys with lifetimes.

How to Configure IP EIGRP Route Authentication

Defining an Autonomous System for EIGRP Route Authentication

Before you begin

Before you configure EIGRP route authentication, you must enable EIGRP. In this task, EIGRP is defined with an autonomous system number.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface type number
  4. no switchport
  5. ip authentication mode eigrp autonomous-system md5
  6. ip authentication key-chain eigrp autonomous-system key-chain
  7. exit
  8. key chain name-of-chain
  9. key key-id
  10. key-string text
  11. accept-lifetime start-time {infinite | end-time | duration seconds }
  12. send-lifetime start-time {infinite | end-time | duration seconds }
  13. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

interface type number

Example:


Device(config)# interface Gigabitethernet 1/0/9

Configures an interface type and enters interface configuration mode.

Step 4

no switchport

Example:

Device(config-if)# no switchport

Puts an interface into Layer 3 mode

Step 5

ip authentication mode eigrp autonomous-system md5

Example:


Device(config-if)# ip authentication mode eigrp 1 md5

Enables MD5 authentication in EIGRP packets.

Step 6

ip authentication key-chain eigrp autonomous-system key-chain

Example:


Device(config-if)# ip authentication key-chain eigrp 1 keychain1

Enables authentication of EIGRP packets.

Step 7

exit

Example:


Device(config-if)# exit

Exits to global configuration mode.

Step 8

key chain name-of-chain

Example:


Device(config)# key chain keychain1

Identifies a key chain and enters key chain configuration mode.

Step 9

key key-id

Example:


Device(config-keychain)# key 1

Identifies the key number and enters key chain key configuration mode.

Step 10

key-string text

Example:


Device(config-keychain-key)# key-string 0987654321

Identifies the key string.

Step 11

accept-lifetime start-time {infinite | end-time | duration seconds }

Example:


Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite

(Optional) Specifies the time period during which the key can be received.

Step 12

send-lifetime start-time {infinite | end-time | duration seconds }

Example:


Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 infinite

(Optional) Specifies the time period during which the key can be sent.

Step 13

end

Example:


Device(config-keychain-key)# end

Exits key chain key configuration mode and returns to privileged EXEC mode.

Defining a Named Configuration for EIGRP Route Authentication

Before you begin

Before you configure EIGRP route authentication, you must enable EIGRP. In this task, EIGRP is defined with a virtual instance name.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. router eigrp virtual-instance-name
  4. Enter one of the following:
    • address-family ipv4 [multicast ] [unicast ] [vrf vrf-name ] autonomous-system autonomous-system-number
    • address-family ipv6 [unicast ] [vrf vrf-name ] autonomous-system autonomous-system-number
  5. network ip-address [wildcard-mask ]
  6. af-interface {default | interface-type interface-number }
  7. authentication key-chain name-of-chain
  8. authentication mode {hmac-sha-256 encryption-type password | md5 }
  9. exit-af-interface
  10. exit-address-family
  11. exit
  12. key chain name-of-chain
  13. key key-id
  14. key-string text
  15. accept-lifetime start-time {infinite | end-time | duration seconds }
  16. send-lifetime start-time {infinite | end-time | duration seconds }
  17. end

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

router eigrp virtual-instance-name

Example:


Device(config)# router eigrp virtual-name1

Enables an EIGRP routing process and enters router configuration mode.

Step 4

Enter one of the following:

  • address-family ipv4 [multicast ] [unicast ] [vrf vrf-name ] autonomous-system autonomous-system-number
  • address-family ipv6 [unicast ] [vrf vrf-name ] autonomous-system autonomous-system-number

Example:


Device(config-router)# address-family ipv4 autonomous-system 45000

Device(config-router)# address-family ipv6 autonomous-system 45000

Enters address family configuration mode to configure an EIGRP IPv4 or IPv6 routing instance.

Step 5

network ip-address [wildcard-mask ]

Example:


Device(config-router-af)# network 172.16.0.0

Associates networks with an EIGRP routing process.

Step 6

af-interface {default | interface-type interface-number }

Example:

Enters address family interface configuration mode and configures interface-specific EIGRP commands.

Step 7

authentication key-chain name-of-chain

Example:


Device(config-router-af-interface)# authentication key-chain SITE1

Specifies an authentication key chain for EIGRP.

Step 8

authentication mode {hmac-sha-256 encryption-type password | md5 }

Example:


Device(config-router-af-interface)# authentication mode md5

Specifies the type of authentication used in an EIGRP address family for the EIGRP instance.

Step 9

exit-af-interface

Example:


Device(config-router-af-interface)# exit-af-interface

Exits address family interface configuration mode.

Step 10

exit-address-family

Example:


Device(config-router-af)# exit-address-family

Exits address family configuration mode.

Step 11

exit

Example:


Device(config-router)# exit

Exits router configuration mode and returns to global configuration mode.

Step 12

key chain name-of-chain

Example:


Device(config)# key chain keychain1

Identifies a key chain and enters key chain configuration mode.

Step 13

key key-id

Example:


Device(config-keychain)# key 1

Identifies the key number and enters key chain key configuration mode.

Step 14

key-string text

Example:


Device(config-keychain-key)# key-string 0987654321

Identifies the key string.

Step 15

accept-lifetime start-time {infinite | end-time | duration seconds }

Example:


Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite

(Optional) Specifies the time period during which the key can be received.

Step 16

send-lifetime start-time {infinite | end-time | duration seconds }

Example:


Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 infinite

(Optional) Specifies the time period during which the key can be sent.

Step 17

end

Example:


Device(config-keychain-key)# end

Exits key chain key configuration mode and returns to privileged EXEC mode.

Configuration Examples for IP EIGRP Route Authentication

Example: EIGRP Route Authentication—Autonomous System Definition

The following example shows how to enable MD5 authentication on EIGRP packets in autonomous system 1.

Device A will accept and attempt to verify the MD5 digest of any EIGRP packet with a key equal to 1. It will also accept a packet with a key equal to 2. All other MD5 packets will be dropped. Device A will send all EIGRP packets with key 2.

Device B will accept key 1 or key 2 and will use key 1 to send MD5 authentication because key 1 is the first valid key of the key chain. Key 1 is not valid after December 4, 2006. After this date, key 2 is used to send MD5 authentication, and this key is valid until January 4, 2007.

The figure below shows the scenario.

Device A Configuration 


Device> enable
Device(config)# configure terminal
Device(config)# router eigrp 1
Device(config-router)# exit
Device(config)# interface Gigabitethernet 1/0/9 
Device(config-if)# no switchport
Device(config-if)# ip authentication mode eigrp 1 md5
Device(config-if)# ip authentication key-chain eigrp 1 key1
Device(config-if)# exit
Device(config)# key chain key1
Device(config-keychain)# key 1
Device(config-keychain-key)# key-string 0987654321
Device(config-keychain-key)# accept-lifetime 04:00:00 Dec 4 2006 infinite
Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 04:48:00 Dec 4 1996
Device(config-keychain-key)# exit
Device(config-keychain)# key 2
Device(config-keychain-key)# key-string 1234567890
Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite
Device(config-keychain-key)# send-lifetime 04:45:00 Jan 4 2007 infinite

Device B Configuration 


Device> enable
Device(config)# configure terminal
Device(config)# router eigrp 1
Device(config-router)# exit
Device(config)# interface Gigabitethernet 1/0/9
Device(config-if)# no switchport
Device(config-if)# ip authentication mode eigrp 1 md5
Device(config-if)# ip authentication key-chain eigrp 1 key2
Device(config-if)# exit
Device(config)# key chain key2
Device(config-keychain)# key 1
Device(config-keychain-key)# key-string 0987654321
Device(config-keychain-key)# accept-lifetime 04:00:00 Dec 4 2006 infinite
Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 infinite
Device(config-keychain-key)# exit
Device(config-keychain)# key 2
Device(config-keychain-key)# key-string 1234567890
Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite
Device(config-keychain-key)# send-lifetime 04:45:00 Jan 4 2007 infinite

Example: EIGRP Route Authentication—Named Configuration

The following example shows how to enable MD5 authentication on EIGRP packets in a named configuration.

Device A will accept and attempt to verify the MD5 digest of any EIGRP packet with a key equal to 1. It will also accept a packet with a key equal to 2. All other MD5 packets will be dropped. Device A will send all EIGRP packets with key 2.

Device B will accept key 1 or key 2 and will use key 1 to send MD5 authentication because key 1 is the first valid key of the key chain. Key 1 is not valid after December 4, 2006. After this date, key 2 will be used to send MD5 authentication because it is valid until January 4, 2007.

Device A Configuration 


Device> enable
Device# configure terminal
Device(config)# router eigrp virtual-name1
Device(config-router)# address-family ipv4 autonomous-system 45000
Device(config-router-af)# network 172.16.0.0
Device(config-router-af)# af-interface Gigabitethernet 1/0/1
Device(config-router-af-interface)# authentication key-chain SITE1
Device(config-router-af-interface)# authentication mode md5
Device(config-router-af-interface)# exit-af-interface
Device(config-router-af)# exit-address-family
Device(config-router)# exit
Device(config)# key chain SITE1
Device(config-keychain)# key 1
Device(config-keychain-key)# key-string 0987654321
Device(config-keychain-key)# accept-lifetime 04:00:00 Dec 4 2006 infinite
Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 infinite
Device(config-keychain-key)# exit
Device(config-keychain)# key 2
Device(config-keychain-key)# key-string 1234567890
Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite
Device(config-keychain-key)# send-lifetime 04:45:00 Jan 4 2007 infinite

Device B Configuration 


Device> enable
Device# configure terminal
Device(config)# router eigrp virtual-name2
Device(config-router)# address-family ipv4 autonomous-system 45000
Device(config-router-af)# network 172.16.0.0
Device(config-router-af)# af-interface ethernet 0/0
Device(config-router-af-interface)# authentication key-chain SITE2
Device(config-router-af-interface)# authentication mode md5
Device(config-router-af-interface)# exit-af-interface
Device(config-router-af)# exit-address-family
Device(config-router)# exit
Device(config)# key chain SITE2
Device(config-keychain)# key 1
Device(config-keychain-key)# key-string 0987654321
Device(config-keychain-key)# accept-lifetime 04:00:00 Jan 4 2007 infinite
Device(config-keychain-key)# send-lifetime 04:00:00 Dec 4 2006 infinite

The following example shows how to configure advanced SHA authentication with password password1 and several key strings that will be rotated as time passes: 


!
key chain chain1
 key 1 
  key-string securetraffic
  accept-lifetime 04:00:00 Dec 4 2006 infinite
  send-lifetime 04:00:00 Dec 4 2010 04:48:00 Dec 4 2008
 !
 key 2
  key-string newertraffic
  accept-lifetime 01:00:00 Dec 4 2010 infinite
  send-lifetime 03:00:00 Dec 4 2010 infinite
 exit
!
router eigrp virtual-name
  address-family ipv6 autonomous-system 4453
    af-interface ethernet 0
       authentication mode hmac-sha-256 0 password1
       authentication key-chain key1
  !
!

Additional References

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Command List, All Releases

EIGRP commands

Cisco IOS IP Routing: EIGRP Command Reference

EIGRP FAQ

EIGRP Frequently Asked Questions

EIGRP Technology White Papers

Enhanced Interior Gateway Routing Protocol

Technical Assistance

Description

Link

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http://www.cisco.com/cisco/web/support/index.html

Feature Information for IP EIGRP Route Authentication

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 EIGRP Route Authentication

Feature Name

Releases

Feature Information

IP Enhanced IGRP Route Authentication

EIGRP route authentication provides MD5 authentication of routing updates from the EIGRP routing protocol. The MD5 keyed digest in each EIGRP packet prevents the introduction of unauthorized or false routing messages from unapproved sources.

The following commands were introduced or modified:

ip authentication key-chain eigrp , ip authentication mode eigrp , show ip eigrp interfaces .