IPv6 Access Services: Stateless DHCPv6

The stateless Dynamic Host Configuration Protocol for IPv6 (DHCPv6) feature allows DHCPv6 to be used for configuring a node with parameters that do not require a server to maintain any dynamic state for the node.

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.

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.

Information About IPv6 Access Services: Stateless DHCPv6

Information Refresh Server Option

The DHCPv6 information refresh option can specify an upper boundary for the length of time a client should wait before refreshing information retrieved from DHCPv6. This option is used with stateless DHCPv6, because there are no addresses or other entities with lifetimes that can tell the client when to contact the DHCPv6 server to refresh its configuration.

SIP Server Options

Session initiation protocol (SIP) server options contain either a list of domain names or IPv6 addresses that can be mapped to one or more SIP outbound proxy servers. One option carries a list of domain names, and the other option carries a list of 128-bit IPv6 addresses.

SIP is an application-layer control protocol that can establish, modify and terminate multimedia sessions or calls. A SIP system has several logical components: user agents, proxy servers, redirect servers, and registrars. User agents may contain SIP clients; proxy servers always contain SIP clients.

SNTP Server Option

The SNTP server option provides a list of one or more IPv6 addresses of SNTP servers available to the client for synchronization. The clients use these SNTP servers to synchronize their system time to that of the standard time servers. The server may list the SNTP servers in decreasing order of preference, but clients must treat the list of SNTP servers as an ordered list.

How to Configure IPv6 Access Services: Stateless DHCPv6

Configuring the Stateless DHCPv6 Function

The server maintains no state related to clients; for example, no prefix pools and records of allocation are maintained. Therefore, this function is “stateless” DHCPv6.

Configuring the Stateless DHCPv6 Server

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    ipv6 dhcp pool poolname

    4.    dns-server ipv6-address

    5.    domain-name domain

    6.    exit

    7.    interface type number

    8.    ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint]

    9.    ipv6 nd other-config flag

    10.    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 ipv6 dhcp pool poolname


    Example:
    Device(config)# ipv6 dhcp pool dhcp-pool
     

    Configures a Dynamic Host Configuration Protocol for IPv6 (DHCPv6) configuration information pool and enters DHCPv6 pool configuration mode.

     
    Step 4 dns-server ipv6-address


    Example:
    Device(config-dhcp)# dns-server 2001:DB8:3000:3000::42
     

    Specifies the Domain Name System (DNS) IPv6 servers available to a DHCPv6 client.

     
    Step 5 domain-name domain


    Example:
    Device(config-dhcp)# domain-name example.com
     

    Configures a domain name for a DHCPv6 client.

     
    Step 6 exit


    Example:
    Device(config-dhcp)# exit
     

    Exits DHCPv6 pool configuration mode, and returns the device to global configuration mode.

     
    Step 7 interface type number


    Example:
    Device(config)# interface serial 3
     

    Specifies an interface type and number, and places the device in interface configuration mode.

     
    Step 8 ipv6 dhcp server poolname [rapid-commit] [preference value] [allow-hint]


    Example:
    Device(config-if)# ipv6 dhcp server dhcp-pool
     

    Enables DHCPv6 on an interface.

     
    Step 9 ipv6 nd other-config flag


    Example:
    Device(config-if)# ipv6 nd other-config flag
     

    Sets the “other stateful configuration” flag in IPv6 router advertisements (RAs).

     
    Step 10 end


    Example:
    Device(config-if)# end
     

    Returns to privileged EXEC mode.

     

    Configuring the Stateless DHCPv6 Client

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface type number

      4.    ipv6 address autoconfig [default]

      5.    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 interface type number


      Example:
      Device(config)# interface serial 3
       

      Specifies an interface type and number, and places the device in interface configuration mode.

       
      Step 4 ipv6 address autoconfig [default]


      Example:
      Device(config-if)# ipv6 address autoconfig
       

      Enables automatic configuration of IPv6 addresses using stateless autoconfiguration on an interface and enables IPv6 processing on the interface.

       
      Step 5 end


      Example:
      Device(config-if)# end
       

      Returns to privileged EXEC mode.

       

      Enabling Processing of Packets with Source Routing Header Options

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    ipv6 source-route

        4.    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 ipv6 source-route


        Example:
        Device(config)# ipv6 source-route
         

        Enables processing of the IPv6 type 0 routing header.

         
        Step 4 end


        Example:
        Device(config-if)# end
         

        Returns to privileged EXEC mode.

         

        Importing Stateless DHCPv6 Server Options

        SUMMARY STEPS

          1.    enable

          2.    configure terminal

          3.    ipv6 dhcp pool poolname

          4.    import dns-server

          5.    import domain-name

          6.    end


        DETAILED STEPS
           Command or ActionPurpose
          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 ipv6 dhcp pool poolname


          Example:
          Router(config)# ipv6 dhcp pool pool1
           

          Configures a DHCPv6 configuration information pool and enters DHCPv6 pool configuration mode.

           
          Step 4 import dns-server


          Example:
          Router(config-dhcp)# import dns-server
           

          Imports the DNS recursive name server option to a DHCPv6 client.

           
          Step 5 import domain-name


          Example:
          Router(config-dhcp)# import domain-name
           

          Imports the domain search list option to a DHCPv6 client.

           
          Step 6 end


          Example:
          Router(config-dhcp)# end
           

          Returns to privileged EXEC mode.

           
          Configuring the SNTP Server Option
          SUMMARY STEPS

            1.    enable

            2.    configure terminal

            3.    ipv6 dhcp pool poolname

            4.    sntp address ipv6-address

            5.    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 ipv6 dhcp pool poolname


            Example:
            Device(config)# ipv6 dhcp pool pool1
             

            Configures a DHCPv6 configuration information pool and enters DHCPv6 pool configuration mode.

             
            Step 4 sntp address ipv6-address


            Example:
            Device(config-dhcp)# sntp address 2001:DB8:2000:2000::33
             

            Specifies the SNTP server list to be sent to the client.

             
            Step 5 end


            Example:
            Device(config-dhcp)# end
             

            Returns to privileged EXEC mode.

             
            Importing SIP Server Information
            SUMMARY STEPS

              1.    enable

              2.    configure terminal

              3.    ipv6 dhcp pool poolname

              4.    import sip address

              5.    import sip domain-name

              6.    end


            DETAILED STEPS
               Command or ActionPurpose
              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 ipv6 dhcp pool poolname


              Example:
              Router(config)# ipv6 dhcp pool pool1
               

              Configures a DHCPv6 configuration information pool and enters DHCPv6 pool configuration mode.

               
              Step 4 import sip address


              Example:
              Router(config-dhcp)# import sip address
               

              Imports the SIP server IPv6 address list option to the outbound SIP proxy server.

               
              Step 5 import sip domain-name


              Example:
              Router(config-dhcp)# import sip domain-name
               

              Imports a SIP server domain-name list option to the outbound SIP proxy server.

               
              Step 6 end


              Example:
              Router(config-dhcp)# end
               

              Returns to privileged EXEC mode.

               
              Importing the SNTP Server Option
              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    ipv6 dhcp pool poolname

                4.    import sntp address ipv6-address

                5.    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 ipv6 dhcp pool poolname


                Example:
                Device(config)# ipv6 dhcp pool pool1
                 

                Configures a DHCPv6 configuration information pool and enters DHCPv6 pool configuration mode.

                 
                Step 4 import sntp address ipv6-address


                Example:
                Device(config-dhcp)# import sntp address 2001:DB8:2000:2000::33
                 

                Imports the SNTP server option to a DHCPv6 client.

                 
                Step 5 end


                Example:
                Device(config-dhcp)# end
                 

                Returns to privileged EXEC mode.

                 

                Configuration Examples for IPv6 Access Services: Stateless DHCPv6

                Example: Configuring the Stateless DHCPv6 Function

                The following example shows how to use the DHCPv6 function to configure clients with information about the name lookup system. The server is configured with a DHCP pool, which contains the name lookup information that is to be passed to clients. It does not need to contain a prefix pool. This DHCP pool is attached to the access link to customers (GigabitEthernet0/0/0) using the ipv6 dhcp server command. The access link also has the ipv6 nd other-config-flag command enabled. RA messages sent from this interface will inform clients that they should use DHCPv6 for “other” (for example, nonaddress) configuration information. 

                ipv6 dhcp pool dhcp-pool 
 dns-server 2001:DB8:A:B::1 
 dns-server 2001:DB8:3000:3000::42 
 domain-name example.com 
! 
interface GigabitEthernet0/0/0
description Access link down to customers 
 ipv6 address 2001:DB8:1234:42::1/64 
 ipv6 nd other-config-flag 
 ipv6 dhcp server dhcp-pool

                The client has no obvious DHCPv6 configuration. However, the ipv6 address autoconfig command on the uplink to the service provider (GigabitEthernet 0/0/0) causes the following two events:

                • Addresses are autoconfigured on the interface, based on prefixes in RA messages received from the server.

                • If received RA messages have the “other configuration” flag set, the interface will attempt to acquire the other (for example, nonaddress) configuration from any DHCPv6 servers.

                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

                MIBs

                MIB

                MIBs Link

                To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

                http:/​/​www.cisco.com/​go/​mibs

                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 IPv6 Access Services: Stateless DHCPv6

                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 IPv6 Access Services: Stateless DHCPv6

                Feature Name

                Releases

                Feature Information

                IPv6 Access Services: Stateless DHCPv6

                Cisco IOS XE Release 2.5

                Cisco IOS XE Release 3.9S

                Stateless DHCPv6 allows DHCPv6 to be used for configuring a node with parameters that do not require a server to maintain any dynamic state for the node.

                The following commands were introduced or modified: dns-server, domain-name, import dns-server, import domain-name, import sip address, import sip domain-name, import sntp address, ipv6 address autoconfig, ipv6 dhcp pool, ipv6 dhcp server, ipv6 nd other-config-flag, ipv6 source-route, sntp address.