IP Routing: EIGRP Configuration Guide, Cisco IOS XE Release 3S
EIGRP Route Tag Enhancements
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EIGRP Route Tag Enhancements

Contents

EIGRP Route Tag Enhancements

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.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table at the end of this module.

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.

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 7Enter 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

              Description

              Link

              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 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 1 Feature Information for Route Tag Enhancement

              Feature Name

              Releases

              Feature Information

              EIGRP Route Tag Enhancements

              15.2(1)E

              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.