EIGRP Route Tag Enhancements

EIGRP Route Tag Enhancements

Last Updated: July 26, 2012

The EIGRP Route Tag Enhancements feature enables you to specify and display route tags in dotted-decimal format, filter routes using the route tag value with wildcard mask, and set a default route tag for all internal Enhanced Interior Gateway Routing Protocol (EIGRP) routes.

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Restrictions for EIGRP Route Tag Enhancements

  • Default route tags are not supported in EIGRP autonomous system configurations.

  • Route tags will not be displayed in dotted-decimal format if the route-tag notation global configuration command is not enabled on the device.

Information About EIGRP Route Tag Enhancements

EIGRP Route Tag Enhancements Overview

A route tag is a 32-bit value attached to routes. Route tags are used to filter routes and apply administrative policies, such as redistribution and route summarization, to tagged routes. You can tag routes within a route map by using the set tag command. You can match tagged routes and apply administrative policies to tagged routes within a route map by using the match tag or match tag list command. The match tag list command is used to match a list of route tags.

Prior to the EIGRP Route Tag Enhancements feature, EIGRP routes could only be tagged using plain decimals (range: 1 to 4294967295). This feature enables users to specify and display route tag values as dotted decimals (range: 0.0.0.0 to 255.255.255.255), similar to the format used by IPv4 addresses. This enhancement is intended to simplify the use of route tags as users can now filter routes by using the route tag wildcard mask.

This feature also allows you to configure a default route tag for all internal EIGRP routes without using route maps. Use the eigrp default-route-tag command in address family configuration mode to configure a default route tag for internal EIGRP routes.

How to Configure EIGRP Route Tag Enhancements

Enabling Dotted-Decimal Notation for Route Tags

Perform this task to enable route tags to be displayed as dotted decimals in show commands, irrespective of whether or not the tags were configured as dotted decimals.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    route-tag notation dotted-decimal

4.    end

5.    Enter one of the following:

  • show ip route tag
  • show ipv6 route tag


DETAILED STEPS
 Command or ActionPurpose
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
route-tag notation dotted-decimal


Example:

Device(config)# route-tag notation dotted-decimal

 

Enables the display of route tags in dotted-decimal format.

 
Step 4
end


Example:

Device(config)# end

 

Exits to privileged EXEC mode.

 
Step 5
Enter one of the following:
  • show ip route tag
  • show ipv6 route tag


Example:

Device# show ip route tag

Device# show ipv6 route tag

 

(Optional) Displays route tag entries for IPv4 or IPv6 routes.

 

Setting a Route Tag in a Route Map

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    route-map map-name [permit | deny] [sequence-number]

4.    set tag {tag-value | tag-value-dotted-decimal}

5.    end

6.    show route-map


DETAILED STEPS
 Command or ActionPurpose
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
route-map map-name [permit | deny] [sequence-number]


Example:

Device(config)# route-map rip-to-eigrp

 

Configures a route map and enters route-map configuration mode.

 
Step 4
set tag {tag-value | tag-value-dotted-decimal}


Example:

Device(config-route-map)# set tag 7.7.7.7

 
Sets a tag value for a route.
Note   In this example, all routes from Routing Information Protocol (RIP) to EIGRP are given a tag value of 7.7.7.7.
 
Step 5
end


Example:

Device(config-route-map)# end

 

Exits to privileged EXEC mode.

 
Step 6
show route-map


Example:

Device# show route-map

 

(Optional) Displays static and dynamic route maps configured on the router.

 

Matching a Route Tag in a Route Map

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    route-map map-name [permit | deny] [sequence-number]

4.    match tag {tag-value | tag-value-dotted-decimal} [...tag-value | tag-value-dotted-decimal]

5.    end

6.    show route-map


DETAILED STEPS
 Command or ActionPurpose
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
route-map map-name [permit | deny] [sequence-number]


Example:

Device(config)# route-map eigrp-to-rip

 

Configures a route map and enters route-map configuration mode.

 
Step 4
match tag {tag-value | tag-value-dotted-decimal} [...tag-value | tag-value-dotted-decimal]


Example:

Device(config-route-map)# match tag 10.10.10.0

 

Filters routes that match specific route tags.

 
Step 5
end


Example:

Device(config-route-map)# end

 

Exits to privileged EXEC mode.

 
Step 6
show route-map


Example:

Device# show route-map

 

(Optional) Displays static and dynamic route maps configured on the device.

 

Creating a Route Tag List

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    route-tag list list-name {deny | permit | sequence number {deny | permit}} tag-dotted-decimal mask

4.    end

5.    show route-tag list [list-name]


DETAILED STEPS
 Command or ActionPurpose
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
route-tag list list-name {deny | permit | sequence number {deny | permit}} tag-dotted-decimal mask


Example:

Device(config)# route-tag list to-rip permit 10.10.10.0 0.0.0.7

 

Creates a route tag list.

  • Route tag lists are used by route maps to match routes based on conditions specified in the route tag lists.
 
Step 4
end


Example:

Device(config)# end

 

Exits to privileged EXEC mode.

 
Step 5
show route-tag list [list-name]


Example:

Device(config-router)# show route-tag list to-rip

 

(Optional) Displays information about route tag lists configured on the device.

  • Use the list-name argument to display information about a specific route tag list.
 

Matching a Route Tag List

Route tag lists are used in route maps to match routes based on conditions specified in the route tag lists. Multiple route tag and mask pair sequences can be configured to permit or deny any condition for a list of route tags.

Note


You can match either a route tag or a route tag list within a single route map sequence.
Perform this task to match routes based on conditions specified in the route tag list.
SUMMARY STEPS

1.    enable

2.    configure terminal

3.    route-tag list list-name {deny | permit | sequence number {deny | permit}} tag-value-dotted-decimal mask

4.    route-map map-name [permit | deny] [sequence-number]

5.    match tag list list-name [...list-name]

6.    end


DETAILED STEPS
 Command or ActionPurpose
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
route-tag list list-name {deny | permit | sequence number {deny | permit}} tag-value-dotted-decimal mask


Example:

Device(config)# route-tag list list1 permit 10.10.10.0 0.0.0.7

 

Configures a route tag list.

 
Step 4
route-map map-name [permit | deny] [sequence-number]


Example:

Device(config)# route-map to-ospf

 

Configures a route map and enters route-map configuration mode.

 
Step 5
match tag list list-name [...list-name]


Example:

Device(config-route-map)# match tag list list1

 

Filters routes that match a specified route tag list.

 
Step 6
end


Example:

Device(config-route-map)# end

 

Exits to privileged EXEC mode.

 

Setting a Default Route Tag for EIGRP Internal Routes

Perform this task to set a default route tag for all internal EIGRP routes without using a route map. Default route tags are supported only in EIGRP named mode configurations.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    router eigrp virtual-name

4.    Enter one of the following:

  • address-family ipv4 unicast autonomous-system autonomous-system-number
  • address-family ipv6 unicast autonomous-system autonomous-system-number

5.    eigrp default-route-tag {route-tag-plain-decimal | route-tag-dotted-decimal}

6.    end

7.   Enter one of the following:

  • show eigrp address-family ipv4 topology
  • show eigrp address-family ipv6 topology


DETAILED STEPS
 Command or ActionPurpose
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-name


Example:

Device(config)# router eigrp name

 

Configures an EIGRP routing process and enters router configuration mode.

 
Step 4
Enter one of the following:
  • address-family ipv4 unicast autonomous-system autonomous-system-number
  • address-family ipv6 unicast autonomous-system autonomous-system-number


Example:

Device(config-router)# address-family ipv4 unicast autonomous-system 1

Device(config-router)# address-family ipv6 unicast autonomous-system 1

 

Enters IPv4 or IPv6 address family configuration mode and configures an EIGRP routing instance.

 
Step 5
eigrp default-route-tag {route-tag-plain-decimal | route-tag-dotted-decimal}


Example:

Device(config-router-af)# eigrp default-route-tag 10

 

Sets a default route tag for all internal EIGRP routes.

 
Step 6
end


Example:

Device(config-router-af)# end

 

Exits to privileged EXEC mode.

 
Step 7
Enter one of the following:
  • show eigrp address-family ipv4 topology
  • show eigrp address-family ipv6 topology


Example:

Device(config-router-af)# show eigrp address-family ipv4 topology

Device(config-router-af)# show eigrp address-family ipv6 topology

 

(Optional) Displays entries of EIGRP address-family IPv4 or IPv6 topology tables.

 

Configuration Examples for EIGRP Route Tag Enhancements

Example: Enabling Dotted-Decimal Notation for Route Tags

The following example shows how to enable the display of route tags in dotted-decimal format by using the route-tag notation command. If you do not configure the route-tag notation command, route tags will be displayed as plain decimals in show commands even if the route tags were configured as dotted decimals. When you configure the route-tag notation command, route tags will be displayed as dotted decimals even if the route tags were configured as plain decimals.

Device# configure terminal
Device(config)# route-tag notation dotted-decimal
      

Example: Setting a Route Tag

The following example shows how to redistribute EIGRP routes into RIP and RIP routes into EIGRP by setting tags for routes within route maps:

Device(config)# route-map eigrp-to-rip
Device(config-route-map)# set tag 10.10.10.10
Device(config-route-map)# exit
Device(config)# route-map rip-to-eigrp
Device(config-route-map)# set tag 20.20.20.20
Device(config-route-map)# exit
Device(config)# router rip
Device(config-router)# redistribute eigrp 7 route-map eigrp-to-rip metric 5
Device(config-router)# exit
Device(config)# router eigrp name
Device(config-router)# address-family ipv4 autonomous-system 10
Device(config-router-af)# topology base
Device(config-router-af-topology)# redistribute rip route-map rip-to-eigrp 2 2 2 2 2
Device(config-router-af-topology)# end

Example: Matching a Route Tag

The following example shows how to redistribute EIGRP routes with a route tag value of 10.10.10.10 into a RIP domain:

Device(config)# route-map eigrp-to-rip
Device(config-route-map)# match tag 10.10.10.10
Device(config-route-map)# exit
Device(config)# router rip
Device(config-router)# redistribute eigrp 7 route-map eigrp-to-rip 5
Device(config-router)# end
      

Example: Configuring a Route Tag List

The following example shows how to configure a route tag list named TAG with various criteria for filtering routes. Route maps will use this list to match routes based on the criteria specified in the list. Route tag lists can accept route tags and wild card masks.

Device(config)# route-tag list TAG permit 1.1.1.1 0.0.0.1
Device(config)# route-tag list TAG seq 3 permit 2.2.2.2 0.0.0.3
Device(config)# route-tag list TAG seq 10 permit 3.3.3.3 0.0.0.7
Device(config)# route-tag list TAG seq 15 5.5.5.5 0.0.0.31
Device(config)# route-tag list TAG seq 20 deny 4.4.4.4 0.0.0.4
 

Example: Matching a Route Tag List

The following example shows how to use a route map to filter routes that match a specific route tag list. A single list can have multiple match criteria. All criteria must match before the route can be filtered. This example shows how to configure a route tag list named List1 in a route map and use the match tag list command to filter routes that match the criteria listed in the route tag list.

Device(config)# route-tag list List1 permit 10.10.10.0 0.0.0.7
Device(config)# route-map to-ospf
Device(config-route-map)# match tag list List1
Device(config-route-map)# exit
Device(config)# router ospf 10
Device(config-router)# redistribute eigrp 7 route-map to-ospf metric 20
Device(config-router)# end

Example: Setting a Default Route Tag

The following example shows how to set a default route tag for all internal EIGRP routes without using a route map. Default route tags are supported only in EIGRP named configurations.

Device(config)# router eigrp name
Device(config-router)# address-family ipv4 unicast autonomous-system 1
Device(config-router-af)# eigrp default-route-tag 10.10.10.10

Additional References

Related Documents

Related Topic Document Title

Cisco IOS commands

Master Command List, All Releases

EIGRP commands

EIGRP Command Reference

Technical Assistance

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

Feature Information for EIGRP Route Tag Enhancements

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 1Feature Information for Route Tag Enhancement
Feature Name Releases Feature Information

EIGRP Route Tag Enhancements

15.2(2)S

The EIGRP Route Tag Enhancements feature enables you to specify and display route tags in dotted-decimal format, filter routes using the route tag wildcard mask, and set a default route tag for all internal Enhanced Interior Gateway Routing Protocol (EIGRP) routes.

The following commands were introduced or modified: eigrp default-route-tag, match tag, match tag list, route-tag list, route-tag notation, set tag (IP), show eigrp address-family topology, show ip eigrp topology, show ipv6 eigrp topology, show ip eigrp vrf topology, show ip route, show ip route tag, show ipv6 route tag, show ip route vrf, show ipv6 route vrf, show route map, and show route-tag list.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: 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. (1110R)

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.

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