IS-IS IPv6 Administrative Tag

The IS-IS IPv6 Administrative Tag feature allows you to assign a tag to IPv6 prefixes that you can use to apply administrative policies with a route map. For example, you can control routes redistributed between area and domain boundaries and between different routing protocols, or apply policies on Intermediate System-to-Intermediate System (IS-IS) routes.

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Information About IS-IS IPv6 Administrative Tag

IS-IS Administrative Tags in IPv6 Prefixes

You can configure an IS-IS administrative tag value for IPv6 prefixes. You can then specify the tag value of IPv6 prefixes that IS-IS inserts into the link-state protocol data units (PDUs) it generates and those that it retrieves from LSPs.

How to Configure an IS-IS IPv6 Administrative Tag

Assigning a Tag to an IS-IS IPv6 Prefix

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    router isis [area-tag]

    4.    net net1

    5.    metric-style wide

    6.    interface [type number]

    7.    ipv6 address {ipv6-address/prefix-length | prefix-name sub-bits/prefix-length}

    8.    ipv6 router isis [area-tag]

    9.    isis ipv6 tag tag-value

    10.    end

    11.    show isis database verbose


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 isis [area-tag]


    Example:
    Device(config)# router isis tag13
     

    Enables the IS-IS routing protocol, specifies an IS-IS process, and enters router configuration mode.

     
    Step 4 net net1


    Example:
    Device(config-router)# net 49.0000.0000.0100.00
     

    Configures an IS-IS network entity table (NET) for the routing process.

     
    Step 5 metric-style wide


    Example:
    Device(config-router)# metric-style wide
     

    Configures a router running IS-IS so that it generates and accepts only new-style type, length, value objects (TLVs).

     
    Step 6 interface [type number]


    Example:
    Device(config-router)# interface GigabitEthernet 0/0/0
     

    Configures an interface and enters interface configuration mode.

     
    Step 7 ipv6 address {ipv6-address/prefix-length | prefix-name sub-bits/prefix-length}


    Example:
    Device(config-if)# ipv6 address 2005::1/64
     

    Configures an IPv6 address based on an IPv6 general prefix and enables IPv6 processing on an interface.

     
    Step 8 ipv6 router isis [area-tag]


    Example:
    Device(config-if)# ipv6 router isis area1
     

    Configures an IS-IS routing process for IPv6 on an interface and attaches an area designator to the routing process.

     
    Step 9 isis ipv6 tag tag-value


    Example:
    Device(config-if)# isis ipv6 tag 200
     

    Configures an administrative tag value that will be associated with an IPv6 address prefix and applied to an IS-IS LSP.

     
    Step 10 end


    Example:
    Device(config-if)# end
     

    (Optional) Saves configuration commands to the running configuration file and returns to privileged EXEC mode.

     
    Step 11 show isis database verbose


    Example:
    Device# show isis database verbose
     

    (Optional) Displays details about the IS-IS link-state database, including the route tag.

    • Enter this command if you want to verify the tag.

     

    Assigning a High Priority Administrative Tag to an IS-IS IPv6 Prefix

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    router isis [area-tag]

      4.    address-family ipv6

      5.    ipv6 route priority high tag tag-value

      6.    exit

      7.    exit


    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 isis [area-tag]


      Example:
      Device(config)# router isis
       

      Configures an IS-IS routing process for IP on an interface, attaches an area designator to the routing process, and enters router configuration mode.

       
      Step 4 address-family ipv6


      Example:
      Device(config-router)# address-family ipv6
       

      Enters address family configuration mode.

       
      Step 5 ipv6 route priority high tag tag-value


      Example:
      Device(config-router-af)# ipv6 route priority high tag 200
       

      Assigns a high priority tag to an IS-IS IPv6 prefix.

       
      Step 6 exit


      Example:
      Device(config-router-af)# exit
       

      (Optional) Exits address family configuration mode, and returns to router configuration mode.

       
      Step 7 exit


      Example:
      Device(config-router)# exit
       

      (Optional) Exits router configuration mode, and returns to global configuration mode.

       

      Using an IS-IS IPv6 Administrative Tag to Redistribute Routes

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    router isis [area-tag]

        4.    address-family ipv6

        5.    redistribute isis [process-id] {level-1 | level-2} into {level-1 | level-2} [distribute-list list-name] [route-map map-tag]

        6.    exit

        7.    exit

        8.    route-map map-tag [permit | deny] [sequence-number]

        9.    match tag tag-value [...tag-value]

        10.    exit


      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 isis [area-tag]


        Example:
        Device(config)# router isis
         

        Configures an IS-IS routing process for IP on an interface, attaches an area designator to the routing process, and enters router configuration mode.

         
        Step 4 address-family ipv6


        Example:
        Device(config-router)# address-family ipv6
         

        Enters address family configuration mode.

         
        Step 5 redistribute isis [process-id] {level-1 | level-2} into {level-1 | level-2} [distribute-list list-name] [route-map map-tag]


        Example:
        Device(config-router-af)# redistribute isis level-1 into level-2 route-map IPV6-PERMIT-TAG
         

        Redistributes IPv6 routes from one routing domain into another routing domain using IS-IS as both the target and source protocol.

         
        Step 6 exit


        Example:
        Device(config-router-af)# exit
         

        (Optional) Exits address family configuration mode, and returns to router configuration mode.

         
        Step 7 exit


        Example:
        Device(config-router)# exit
         

        (Optional) Exits router configuration mode, and returns to global configuration mode.

         
        Step 8 route-map map-tag [permit | deny] [sequence-number]


        Example:
        Device(config)# route-map match-tag
         

        Defines the conditions for redistributing routes from one routing protocol into another or from one IS-IS level to another.

        • This command causes the router to enter route-map configuration mode.

         
        Step 9 match tag tag-value [...tag-value]


        Example:
        Device(config-route-map)# match tag 100
         

        Matches routes tagged with the specified tag numbers.

        • If you are setting a tag for the first time, you cannot match on tag; this step is an option if you are changing tags.

         
        Step 10 exit


        Example:
        Device(config-route-map)# exit
         

        (Optional) Exits route-map configuration mode, and returns to global configuration mode.

         

        Using an IS-IS IPv6 Administrative Tag to Configure Routes

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    ipv6 route [vrf vrf-name] ipv6-prefix/prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [nexthop-vrf [vrf-name | default]] [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]

          4.    router isis [area-tag]

          5.    address-family ipv6

          6.    redistribute isis [process-id] {level-1 | level-2} into {level-1 | level-2} [distribute-list list-name] [route-map map-tag

          7.    exit

          8.    exit

          9.    route-map map-tag [permit | deny] [sequence-number]

          10.    set tag tag-value

          11.    exit


        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 ipv6 route [vrf vrf-name] ipv6-prefix/prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [nexthop-vrf [vrf-name | default]] [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]


          Example:
          Router(config)# ipv6 route  2033::1/64 GigabitEthernet 0/0/0
           

          Establishes a static IPv6 routes.

           
          Step 4 router isis [area-tag]


          Example:
          Device(config)# router isis
           

          Configures an IS-IS routing process for IP on an interface, attaches an area designator to the routing process, and enters router configuration mode.

           
          Step 5 address-family ipv6


          Example:
          Device(config-router)# address-family ipv6
           

          Enters address family configuration mode.

           
          Step 6 redistribute isis [process-id] {level-1 | level-2} into {level-1 | level-2} [distribute-list list-name] [route-map map-tag


          Example:
          Device(config-router-af)# redistribute isis level-1 into level-2 route-map IPV6-PERMIT-TAG
           

          Redistributes IPv6 routes from one routing domain into another routing domain using IS-IS as both the target and source protocol.

           
          Step 7 exit


          Example:
          Device(config-router-af)# exit
           

          (Optional) Exits address family configuration mode, and returns to router configuration mode.

           
          Step 8 exit


          Example:
          Device(config-router)# exit
           

          (Optional) Exits router configuration mode, and returns to global configuration mode.

           
          Step 9 route-map map-tag [permit | deny] [sequence-number]


          Example:
          Router(config)# route-map set-tag
           

          Defines the conditions for redistributing routes from one routing protocol into another or from one IS-IS level to another.

          • This command causes the router to enter route-map configuration mode.

           
          Step 10 set tag tag-value


          Example:
          Router(config-route-map)# set tag 300
           

          Sets a tag value of the destination routing protocol.

           
          Step 11 exit


          Example:
          Device(config-route-map)# exit
           

          (Optional) Exits route-map configuration mode, and returns to global configuration mode.

           

          Applying an IS-IS IPv6 Tag to a Summary Prefix

          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    router isis [area-tag]

            4.    address-family ipv6

            5.    ipv6 route [vrf vrf-name] ipv6-prefix / prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [nexthop-vrf [vrf-name | default]] [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]

            6.    exit

            7.    exit

            8.    router isis [area-tag]

            9.    address-family ipv6

            10.    redistribute isis [process-id] {level-1| level-2} into {level-1 |level-2} distribute-list list-name

            11.    summary-prefix ipv6-prefix/ prefix-length {level-1 | level-1-2| level-2} tag tag-value

            12.    end

            13.    show isis database verbose


          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 isis [area-tag]


            Example:
            Device(config)# router isis
             

            Configures an IS-IS routing process for IP on an interface, attaches an area designator to the routing process, and enters router configuration mode.

             
            Step 4 address-family ipv6


            Example:
            Device(config-router)# address-family ipv6
             

            Enters address family configuration mode.

             
            Step 5 ipv6 route [vrf vrf-name] ipv6-prefix / prefix-length {ipv6-address | interface-type interface-number [ipv6-address]} [nexthop-vrf [vrf-name | default]] [administrative-distance] [administrative-multicast-distance | unicast | multicast] [next-hop-address] [tag tag]


            Example:
            Device(config-router-af)# ipv6 route 11:1:1:1:1:1::/96 GigabitEthernet 0/0/0
             

            Establishes a static IPv6 routes.

             
            Step 6 exit


            Example:
            Device(config-router-af)# exit
             

            (Optional) Exits address family configuration mode, and returns to router configuration mode.

             
            Step 7 exit


            Example:
            Device(config-router)# exit
             

            (Optional) Exits router configuration mode, and returns to global configuration mode.

             
            Step 8 router isis [area-tag]


            Example:
            Device(config)# router isis
             

            Configures an IS-IS routing process for IP on an interface, attaches an area designator to the routing process, and enters router configuration mode.

             
            Step 9 address-family ipv6


            Example:
            Device(config-router)# address-family ipv6
             

            Enters address family configuration mode.

             
            Step 10 redistribute isis [process-id] {level-1| level-2} into {level-1 |level-2} distribute-list list-name


            Example:
            Device(config-router-af)# redistribute static level-2 metric 50
             

            Redistributes IPv6 routes from one routing domain into another routing domain using IS-IS as both the target and source protocol.

             
            Step 11 summary-prefix ipv6-prefix/ prefix-length {level-1 | level-1-2| level-2} tag tag-value


            Example:
            Device(config-router-af)# summary-prefix 11:1:1:1::/64 tag 600
             

            Allows a Level 1-2 router to summarize Level 1 prefixes at Level 2, instead of advertising the Level 1 prefixes directly when the router advertises the summary.

            • The ipv6-prefix argument in the summary-prefix command must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

            • The prefix-length argument is a decimal value that indicates how many of the high-order contiguous bits of the address comprise the prefix (the network portion of the address). A slash mark must precede the decimal value.

             
            Step 12 end


            Example:
            Device(config-router-af)# end
             

            (Optional) Saves configuration commands to the running configuration file and returns to privileged EXEC mode.

             
            Step 13 show isis database verbose


            Example:
            Device# show isis database verbose
             

            (Optional) Displays details about the IS-IS link-state database, including the route tag.

            • Perform this step if you want to verify the tag.

             

            Configuration Examples for IS-IS IPv6 Administrative Tag

            Example: Assigning a Tag to an IS-IS IPv6 Prefix

            Device(config)# router isis
Device(config-router)# net 49.0000.0000.0100.00
Device(config-router)# metric-style wide
Device(config-router)# interface GigabitEthernet 0/0/0
Device(config-if)# ipv6 address 2005::1/64
Device(config-if)# ipv6 router isis
Device(config-if)# isis ipv6 tag 200
Device(config-if)# end
Device# show isis database verbose

IS-IS Level-1 Link State Database:
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime      ATT/P/OL
Device.00-00     * 0x00000001   0xD27D        1189              0/0/0
  Area Address: 49
  NLPID:        0x8E 
  Hostname: Device
  IPv6 Address: 2005::1
  Metric: 10         IPv6 2005::/64
    Route Admin Tag: 200
IS-IS Level-2 Link State Database:
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime      ATT/P/OL
Device.00-00     * 0x00000001   0xD27D        1189              0/0/0
  Area Address: 49
  NLPID:        0x8E 
  Hostname: Device
  IPv6 Address: 2005::1
  Metric: 10         IPv6 2005::/64
    Route Admin Tag: 200

            Example: Assigning a High Priority Administrative Tag to an IS-IS IPv6 Prefix

            Device(config)# router isis
Device(config-router)# address-family ipv6
Device(config-router-af)# ipv6 route priority high tag 200

            Example: Using an IS-IS IPv6 Administrative Tag to Redistribute Routes

            Device(config)# router isis
Device(config-router)# address-family ipv6
Device(config-router-af)# redistribute isis level-1 into level-2 route-map match-tag
Device(config-router-af)# route-map match-tag
Device(config-route-map)# match tag 100

            Example: Using an IS-IS IPv6 Administrative Tag to Configure Routes

            Device(config)# ipv6 route 2033::1/64 GigabitEthernet 0/0/0
Device(config)# router isis
Device(config-router)# address-family ipv6
Device(config-router-af)# redistribute static level-2 route-map set-tag
Device(config-router-af)# route-map set-tag
Device(config-route-map)# set tag 300
Device(config-route-map)# end
Device# show isis database verbose level-2

Device.00-00     * 0x0000004E   0x9805        1197              0/0/0
  Area Address: 33
  NLPID:        0xCC 0x8E 
  Hostname: Device
  IP Address:   10.100.100.20
  IPv6 Address: 2001:DB8::100
  IPv6 Address: 2001:DB8::200
  Metric: 10         IS-Extended route500.01
  Metric: 10         IP 10.100.100.0/24
  Metric: 10         IPv6 2001:DB8::/64
  Metric: 10         IPv6 2001:DB8::/64
  Metric: 10         IPv6-Interarea 11:1:1:1:1:1:1:1/128
  Metric: 20         IPv6-Interarea 2003:DB8::/64
  Metric: 0          IPv6 2033::/64
    Route Admin Tag: 300

            Example: Applying an IS-IS IPv6 Administrative Tag to a Summary Prefix

            Device(config)# router isis
Device(config)# ipv6 route 11:1:1:1:1:1::/96 GigabitEthernet 0/0/0
Device(config)# router isis
Device(config-router)# address-family ipv6
Device(config-router-af)# redistribute static level-2 metric 50
Device(config-router-af)# summary-prefix 11:1:1:1::/64 tag 600
Device(config-route-map)# end
Device# show isis database verbose level-2
 
IS-IS Level-2 Link State Database:
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime      ATT/P/OL
Device.00-00     * 0x00000007   0x4AA7        1174              0/0/0
  Area Address: 33
  NLPID:        0xCC 0x8E 
  Hostname: Device
  IP Address:   10.100.100.20
  IPv6 Address: 2001:DB8::100
  IPv6 Address: 2001:DB8::200
  Metric: 10         IS-Extended route500.01
  Metric: 10         IP 10.100.100.0/24
  Metric: 10         IPv6 2001:DB8::/64
  Metric: 10         IPv6 2001:DB8::/64
  Metric: 10         IPv6 11:1:1:1::/64
    Route Admin Tag: 600
(Summary route 11:1:1:1::/64 is advertised with tag 600)
Device(config-router-af)#

            Additional References

            Related Documents

            Related Topic

            Document Title

            IPv6 addressing and connectivity

            IPv6 Configuration Guide

            Cisco IOS commands

            Cisco IOS Master Commands List, All Releases

            IPv6 commands

            Cisco IOS IPv6 Command Reference

            Cisco IOS IPv6 features

            Cisco IOS IPv6 Feature Mapping

            Standards and RFCs

            Standard/RFC

            Title

            RFCs for IPv6

            IPv6 RFCs

            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 IS-IS IPv6 Administrative Tag

            Feature Name

            Releases

            Feature Information

            IS-IS IPv6 Administrative Tag

            15.2(4)M

            15.2(4)S

            15.2(1)SY

            Allows you to assign a tag to IPv6 prefixes that you can use to apply administrative policy with a route map.

            The following commands were introduced or modified: ipv6 route priority high, isis ipv6 tag, redistribute isis (ipv6), show isis database verbose, summary-prefix (ipv6 IS-IS).