IPv6 Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3850 Switches)
Configuring IPv6 Client IP Address Learning
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Contents

Configuring IPv6 Client IP Address Learning

Prerequisites for IPv6 Client Address Learning

Before configuring IPv6 client address learning, configure the wireless clients to support IPv6.

Information About IPv6 Client Address Learning

Client Address Learning is configured on switch to learn the wireless client's IPv4 and IPv6 address and clients transition state maintained by the switch on an association, re-association, de-authentication and timeout.

There are three ways for IPv6 client to acquire IPv6 addresses:

  • Stateless Address Auto-Configuration (SLACC)
  • Stateful DHCPv6
  • Static Configuration

For all of these methods, the IPv6 client always sends neighbor solicitation DAD (Duplicate Address Detection) request to ensure there is no duplicate IP address on the network. The switch snoops the client's NDP and DHCPv6 packets to learn about its client IP addresses.

SLAAC Address Assignment

The most common method for IPv6 client address assignment is Stateless Address Auto-Configuration (SLAAC). SLAAC provides simple plug-and-play connectivity where clients self-assign an address based on the IPv6 prefix. This process is achieved

Stateless Address Auto-Configuration (SLAAC) is configured as follows:

  • Host sends a router solicitation message.
  • Hosts waits for a Router Advertisement message.
  • Hosts take the first 64 bits of the IPv6 prefix from the Router Advertisement message and combines it with the 64 bit EUI-64 address (in the case of ethernet, this is created from the MAC Address) to create a global unicast message. The host also uses the source IP address, in the IP header, of the Router Advertisement message, as its default gateway.
  • Duplicate Address Detection is performed by IPv6 clients in order to ensure that random addresses that are picked do not collide with other clients.
  • The choice of algorithm is up to the client and is often configurable.

The last 64 bits of the IP v6 address can be learned based on the following 2 algorithms:

  • EUI-64 which is based on the MAC address of the interface, or
  • Private addresses that are randomly generated.
Figure 1. SLAAC Address Assignment



The following Cisco IOS configuration commands from a Cisco-capable IPv6 router are used to enable SLAAC addressing and router advertisements:

ipv6 unicast-routing
interface Vlan20
description IPv6-SLAAC
ip address 192.168.20.1 255.255.255.0
ipv6 address FE80:DB8:0:20::1 linklocal
ipv6 address 2001:DB8:0:20::1/64
ipv6 enable
end

Stateful DHCPv6 Address Assignment

Figure 2. Stateful DHCPv6 Address Assignment

The use of DHCPv6 is not required for IPv6 client connectivity if SLAAC is already deployed. There are two modes of operation for DHCPv6 called Stateless and Stateful.

The DHCPv6 Stateless mode is used to provide clients with additional network information that is not available in the router advertisement, but not an IPv6 address as this is already provided by SLAAC. This information can include the DNS domain name, DNS server(s), and other DHCP vendor-specific options. This interface configuration is for a Cisco IOS IPv6 router implementing stateless DHCPv6 with SLAAC enabled:

ipv6 unicast-routing
ipv6 dhcp pool IPV6_DHCPPOOL
address prefix 2001:db8:5:10::/64
domain-name cisco.com
dns-server 2001:db8:6:6::1
interface Vlan20
description IPv6-DHCP-Stateless
ip address 192.168.20.1 255.255.255.0
ipv6 nd other-config-flag
ipv6 dhcp server IPV6_DHCPPOOL
ipv6 address 2001:DB8:0:20::1/64
end

The DHCPv6 Stateful option, also known as managed mode, operates similarly to DHCPv4 in that it assigns unique addresses to each client instead of the client generating the last 64 bits of the address as in SLAAC. This interface configuration is for a Cisco IOS IPv6 router implementing stateful DHCPv6 on a local Switch:

ipv6 unicast-routing
ipv6 dhcp pool IPV6_DHCPPOOL
address prefix 2001:db8:5:10::/64
domain-name cisco.com
dns-server 2001:db8:6:6::1
interface Vlan20
description IPv6-DHCP-Stateful
ip address 192.168.20.1 255.255.255.0
ipv6 address 2001:DB8:0:20::1/64
ipv6 nd prefix 2001:DB8:0:20::/64 no-advertise
ipv6 nd managed-config-flag
ipv6 nd other-config-flag
ipv6 dhcp server IPV6_DHCPPOOL
end

This interface configuration is for a Cisco IOS IPv6 router implementing stateful DHCPv6 on an external DHCP server:

ipv6 unicast-routing
domain-name cisco.com
dns-server 2001:db8:6:6::1
interface Vlan20
description IPv6-DHCP-Stateful
ip address 192.168.20.1 255.255.255.0
ipv6 address 2001:DB8:0:20::1/64
ipv6 nd prefix 2001:DB8:0:20::/64 no-advertise
ipv6 nd managed-config-flag
ipv6 nd other-config-flag
ipv6 dhcp_relay destination 2001:DB8:0:20::2
end

Static IP Address Assignment

Statically configured address on a client.

Router Solicitation

A Router Solicitation message is issued by a host controller to facilitate local routers to transmit Router Advertisement from which it can obtain information about local routing or perform Stateless Auto-configuration. Router Advertisements are transmitted periodically and the host prompts with an immediate Router Advertisement using a Router Solicitation such as - when it boots or following a restart operation.

Router Advertisement

A Router Advertisement message is issued periodically by a router or in response to a Router Solicitation message from a host. The information contained in these messages is used by hosts to perform Stateless Auto-configuration and to modify its routing table.

Neighbor Discovery

IPv6 Neighbor Discovery is a set of messages and processes that determine relationships between neighboring nodes. Neighbor Discovery replaces ARP, ICMP Router Discovery, and ICMP Redirect used in IPv4.

IPv6 Neighbor Discovery inspection analyzes neighbor discovery messages in order to build a trusted binding table database, and IPv6 neighbor discovery packets that do not comply are dropped. The neighbor binding table in the switch tracks each IPv6 address and its associated MAC address. Clients are expired from the table according to Neighbor Binding timers.

Neighbor Discovery Suppression

The IPv6 addresses of wireless clients are cached by the switch. When the switch receives an NS multicast looking for an IPv6 address, and if the target address is known to the switch and belongs to one of its clients, the switch will reply with an NA message on behalf of the client. The result of this process generates the equivalent of the Address Resolution Protocol (ARP) table of IPv4 but is more efficient - uses generally fewer messages.


Note


The switch acts like proxy and respond with NA, only when the ipv6 nd suppress command is configured

If the switch does not have the IPv6 address of a wireless client, the switch will not respond with NA and forward the NS packet to the wireless side. To resolve this, an NS Multicast Forwarding knob is provided. If this knob is enabled, the switch gets the NS packet for the IPv6 address that it does not have (cache miss) and forwards it to the wireless side. This packet reaches the intended wireless client and the client replies with NA.

This cache miss scenario occurs rarely, and only very few clients which do not implement complete IPv6 stack may not advertise their IPv6 address during NDP.

RA Guard

IPv6 clients configure IPv6 addresses and populate their router tables based on IPv6 router advertisement (RA) packets. The RA guard feature is similar to the RA guard feature of wired networks. RA guard increases the security of the IPv6 network by dropping the unwanted or rogue RA packets that come from wireless clients. If this feature is not configured, malicious IPv6 wireless clients announce themselves as the router for the network often with high priority, which would take higher precedence over legitimate IPv6 routers.

RA-Guard also examines the incoming RA's and decides whether to switch or block them based solely on information found in the message or in the switch configuration. The information available in the frames received is useful for RA validation:
  • Port on which the frame is received
  • IPv6 source address
  • Prefix list

The following configuration information created on the switch is available to RA-Guard to validate against the information found in the received RA frame:

  • Trusted/Untrusted ports for receiving RA-guard messages
  • Trusted/Untrusted IPv6 source addresses of RA-sender
  • Trusted/Untrusted Prefix list and Prefix ranges
  • Router Preference

RA guard occurs at the switch. You can configure the switch to drop RA messages at the switch. All IPv6 RA messages are dropped, which protects other wireless clients and upstream wired network from malicious IPv6 clients.

//Create a policy for RA Guard//
ipv6 nd raguard policy raguard-router
trusted-port
device-role router
//Applying the RA Guard Policy on port/interface//
interface tengigabitethernet1/0/1 (Katana)
interface gigabitethernet1/0/1 (Edison)

ipv6 nd raguard attach-policy raguard-router

RA Throttling

RA throttling allows the controller to enforce limits to RA packets headed toward the wireless network. By enabling RA throttling, routers that send many RA packets can be trimmed to a minimum frequency that will still maintain an IPv6 client connectivity. If a client sends an RS packet, an RA is sent back to the client. This RA is allowed through the controller and unicasted to the client. This process ensures that the new clients or roaming clients are not affected by the RA throttling.

Configuring IPv6 Unicast (CLI)

IPv6 unicasting must always be enabled on the switch and the controller. IPv6 unicast routing is disabled.

Before You Begin

To enable the forwarding of IPv6 unicast datagrams, use the ipv6 unicast-routing command in global configuration mode. To disable the forwarding of IPv6 unicast datagrams, use the no form of this command.

SUMMARY STEPS

    1.    configure terminal

    2.    ipv6 unicast routing


DETAILED STEPS
      Command or Action Purpose
    Step 1 configure terminal


    Example:
    
                
              
    Switch# configure terminal
    
    
     

    Enters the global configuration mode.

     
    Step 2 ipv6 unicast routing


    Example:
    Switch (config)# ipv6 unicast routing
     
    enable the forwarding of IPv6 unicast datagrams  

    Configuring RA Guard Policy (CLI)

    Configure RA Guard policy on the switch to add IPv6 client addresses and populate the router table based on IPv6 router advertisement packets.

    Before You Begin
    SUMMARY STEPS

      1.    configure terminal

      2.    ipv6 nd raguard policy raguard-router

      3.    trustedport

      4.    device-role router

      5.    exit


    DETAILED STEPS
        Command or Action Purpose
      Step 1 configure terminal


      Example:
      
                  
                
      Switch# configure terminal
      
      
       

      Enters the global configuration mode.

       
      Step 2 ipv6 nd raguard policy raguard-router


      Example:
      Switch(config)# ipv6 nd raguard policy raguard-router
       
      Defines the RA guard policy name and enters RA guard policy configuration mode.  
      Step 3 trustedport


      Example:
      Switch(config-ra-guard)# trustedport
       
      (Optional) Specifies that this policy is being applied to trusted ports.  
      Step 4 device-role router


      Example:
      Switch(config-ra-guard)# device-role router
       
      Specifies the role of the device attached to the port.  
      Step 5 exit


      Example:
      Switch(config-ra-guard)# exit
       
      Exits RA guard policy configuration mode and returns to global configuration mode.  

      Applying RA Guard Policy (CLI)

      Applying the RA Guard policy on the switch will block all the untrusted RA's.

      Before You Begin
      SUMMARY STEPS

        1.    configure terminal

        2.    interface tengigabitethernet 1/0/1

        3.    ipv6 nd raguard attach-policy raguard-router

        4.    exit


      DETAILED STEPS
          Command or Action Purpose
        Step 1 configure terminal


        Example:
        
                    
                  
        Switch# configure terminal
        
        
         

        Enters the global configuration mode.

         
        Step 2 interface tengigabitethernet 1/0/1


        Example:
        Switch (config)# interface tengigabitethernet 1/0/1
         
        Specifies an interface type and number, and places the device in interface configuration mode.  
        Step 3 ipv6 nd raguard attach-policy raguard-router


        Example:
        Switch(config-if)# ipv6 nd raguard attach-policy raguard-router
         
        Applies the IPv6 RA Guard feature to a specified interface.  
        Step 4 exit


        Example:
        Switch(config-if)# exit
         
        Exits interface configuration mode.  

        Configuring RA Throttle Policy (CLI)

        Configure RA Throttle policy to allow the enforce the limits

        Before You Begin
        SUMMARY STEPS

          1.    configure terminal

          2.    ipv6 nd ra-throttler policy ra-throttler1

          3.    throttleperiod500

          4.    max-through10

          5.    allow-atleast 5 at-most 10


        DETAILED STEPS
            Command or Action Purpose
          Step 1 configure terminal


          Example:
          
                      
                    
          Switch# configure terminal
          
          
           

          Enters the global configuration mode.

           
          Step 2 ipv6 nd ra-throttler policy ra-throttler1


          Example:
          Switch(config)# ipv6 nd ra-throttler policy ra-throttler1
           
          Define the router advertisement (RA) throttler policy name and enter IPv6 RA throttle policy configuration mode.  
          Step 3 throttleperiod500


          Example:
          Switch(config-nd-ra-throttle)# throttleperiod 500
           
          Configures the throttle period in an IPv6 RA throttler policy.  
          Step 4 max-through10


          Example:
          Switch(config-nd-ra-throttle)# max-through 500
           
          Limits multicast RAs per VLAN per throttle period.  
          Step 5 allow-atleast 5 at-most 10


          Example:
          Switch(config-nd-ra-throttle)# allow-atleast 5 at-most 10
           
          Limits the number of multicast RAs per device per throttle period in an RA throttler policy.  

          Applying RA Throttle Policy on VLAN (CLI)

          Applying the RA Throttle policy on a VLAN. By enabling RA throttling, routers that send many RA packets can be trimmed to a minimum frequency that will still maintain an IPv6 client connectivity.

          Before You Begin
          SUMMARY STEPS

            1.    configure terminal

            2.    vlan configuration 1

            3.    ipv6 nd ra throttler attach-policy ra-throttler1


          DETAILED STEPS
              Command or Action Purpose
            Step 1 configure terminal


            Example:
            
                        
                      
            Switch# configure terminal
            
            
             

            Enters the global configuration mode.

             
            Step 2 vlan configuration 1


            Example:
            Switch(config)# vlan configuration 1
             
            Configures a VLAN or a collection of VLANs and enters VLAN configuration mode.  
            Step 3 ipv6 nd ra throttler attach-policy ra-throttler1


            Example:
            Switch(config-vlan)# ipv6 nd ra throttler attach-policy ra-throttler1
             
            Attaches an IPv6 RA throttler policy to a VLAN or a collection of VLANs.  
            Related Concepts

            Configuring IPv6 Snooping (CLI)

            IPv6 snooping must always be enabled on the switch and the controller.

            Before You Begin

            Enable IPv6 on the client machine.

            SUMMARY STEPS

              1.    vlan configuration 1

              2.    ipv6 snooping

              3.    ipv6 nd suppress

              4.    exit


            DETAILED STEPS
                Command or Action Purpose
              Step 1 vlan configuration 1


              Example:
              Switch(config)# vlan configuration 1
               

              Enters Vlan configuration mode.

               
              Step 2 ipv6 snooping


              Example:
              Switch(config-vlan)# ipv6 snooping
               

              Enables IPv6 snooping on the Vlan.

               
              Step 3 ipv6 nd suppress


              Example:
              Switch(config-vlan-config)# ipv6 nd suppress
               

              Enables the IPv6 ND suppress on the Vlan.

               
              Step 4 exit


              Example:
              Switch(config-vlan-config)# exit
              
               

              Saves the configuration and comes out of the Vlan configuration mode.

               

              Configuring IPv6 ND Suppress Policy (CLI)

              The IPv6 neighbor discovery (ND) multicast suppress feature stops as many ND multicast neighbor solicit (NS) messages as possible by dropping them (and responding to solicitations on behalf of the targets) or converting them into unicast traffic. This feature runs on a layer 2 switch or a wireless controller and is used to reduce the amount of control traffic necessary for proper link operations.

              When an address is inserted into the binding table, an address resolution request sent to a multicast address is intercepted, and the device either responds on behalf of the address owner or, at layer 2, converts the request into a unicast message and forwards it to its destination.

              Before You Begin
              SUMMARY STEPS

                1.    enable

                2.    configure terminal

                3.    ipv6 nd suppress policy


              DETAILED STEPS
                  Command or Action Purpose
                Step 1 enable


                Example:
                Switch(config)# enable
                 
                Enables privileged EXEC mode.
                • Enter your password if prompted.
                 
                Step 2 configure terminal


                Example:
                
                            
                          
                Switch# configure terminal
                
                
                 

                Enters the global configuration mode.

                 
                Step 3 ipv6 nd suppress policy


                Example:
                Switch (config)# ipv6 nd suppress policy
                 

                Defines the ND suppress policy name and enters ND suppress policy configuration mode.

                 

                Configuring IPv6 Snooping on VLAN/PortChannel

                Neighbor Discover (ND) suppress can be enabled or disabled on either the VLAN or a switchport.

                Before You Begin

                SUMMARY STEPS

                  1.    vlan config901

                  2.    ipv6 nd suppress

                  3.    end

                  4.    interface gi1/0/1

                  5.    ipv6 nd suppress

                  6.    end


                DETAILED STEPS
                    Command or Action Purpose
                  Step 1 vlan config901


                  Example:
                  Switch(config)# vlan config901
                   
                  Creates a VLAN and enter the VLAN configuration mode  
                  Step 2 ipv6 nd suppress


                  Example:
                  Switch(config-vlan)# ipv6 nd suppress
                   
                  Applies the IPv6 nd suppress on VLAN.  
                  Step 3 end


                  Example:
                  Switch(config-vlan)# end
                   
                  Exits vlan configuration mode and enters the global configuration mode.  
                  Step 4 interface gi1/0/1


                  Example:
                  Switch (config)# interface gi1/0/1
                   

                  Creates a gigabitethernet port interface.

                   
                  Step 5 ipv6 nd suppress


                  Example:
                  Switch(config-vlan)# ipv6 nd suppress
                   
                  Applies the IPv6 nd suppress on the interface.  
                  Step 6 end


                  Example:
                  Switch(config-vlan)# end
                   
                  Exits vlan configuration mode and enters the global configuration mode.  

                  Configuring IPv6 on Switch (CLI)

                  Use this configuration example to configure IPv6 on an interface.

                  Before You Begin

                  Enable IPv6 on the client and IPv6 support on the wired infrastructure.

                  SUMMARY STEPS

                    1.    interface vlan 1

                    2.    ip address fe80::1 link-local

                    3.    ipv6 enable

                    4.    end


                  DETAILED STEPS
                      Command or Action Purpose
                    Step 1 interface vlan 1


                    Example:
                    Switch(config)# interface vlan 1
                    
                     

                    Creates a interface and enters interface configuration mode.

                     
                    Step 2 ip address fe80::1 link-local


                    Example:
                    Switch(config-if)# ip address 198.51.100.1 255.255.255.0
                       Switch(config-if)# ipv6 address fe80::1 link-local
                       Switch(config-if)# ipv6 address 2001:DB8:0:1:FFFF:1234::5/64 
                       Switch(config-if)# ipv6 address 2001:DB8:0:0:E000::F/64
                     

                    Configures IPv6 address on the interface using the link-local option.

                     
                    Step 3 ipv6 enable


                    Example:
                    Switch(config)# ipv6 enable
                    
                     

                    (Optional) Enables IPv6 on the interface.

                     
                    Step 4 end


                    Example:
                    Switch(config)# end
                     

                    Exits from the interface mode.

                     

                    Configuring DHCP Pool (CLI)

                    SUMMARY STEPS

                      1.    ipv6 dhcp pool Vlan21

                      2.    address prefix 2001:DB8:0:1:FFFF:1234::/64 lifetime 300 10

                      3.    dns-server 2001:100:0:1::1

                      4.    domain-name example.com

                      5.    end


                    DETAILED STEPS
                        Command or Action Purpose
                      Step 1 ipv6 dhcp pool Vlan21


                      Example:
                      Switch(config)# ipv6 dhcp pool vlan1
                      
                       

                      Enters the configuration mode and configures the IPv6 DHCP pool on the Vlan.

                       
                      Step 2 address prefix 2001:DB8:0:1:FFFF:1234::/64 lifetime 300 10


                      Example:
                      Switch(config-dhcpv6)# address prefix 2001:DB8:0:1:FFFF:1234::/64 lifetime 300 10
                      
                       

                      Enters the configuration-dhcp mode and configures the address pool and its lifetime on a Vlan.

                       
                      Step 3 dns-server 2001:100:0:1::1


                      Example:
                      Switch(config-dhcpv6)# dns-server 2001:20:21::1
                       

                      Configures the DNS servers for the DHCP pool.

                       
                      Step 4 domain-name example.com


                      Example:
                      Switch(config-dhcpv6)# domain-name example.com
                       

                      Configures the domain name to complete unqualified host names.

                       
                      Step 5 end


                      Example:
                      Switch(config)# end
                       

                      Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-Z to exit global configuration mode.

                       

                      Configuring Stateless Auto Address Configuration Without DHCP (CLI)

                      SUMMARY STEPS

                        1.    interface vlan 1

                        2.    ip address fe80::1 link-local

                        3.    ipv6 enable

                        4.    no ipv6 nd managed-config-flag

                        5.    no ipv6 nd other-config-flag

                        6.    end


                      DETAILED STEPS
                          Command or Action Purpose
                        Step 1 interface vlan 1


                        Example:
                        Switch(config)# interface vlan 1
                        
                         

                        Creates a interface and enters interface configuration mode.

                         
                        Step 2 ip address fe80::1 link-local


                        Example:
                        Switch(config-if)# ip address 198.51.100.1 255.255.255.0
                           Switch(config-if)# ipv6 address fe80::1 link-local
                           Switch(config-if)# ipv6 address 2001:DB8:0:1:FFFF:1234::5/64 
                           Switch(config-if)# ipv6 address 2001:DB8:0:0:E000::F/64
                         

                        Configures IPv6 address on the interface using the link-local option.

                         
                        Step 3 ipv6 enable


                        Example:
                        Switch(config)# ipv6 enable
                        
                         

                        (Optional) Enables IPv6 on the interface.

                         
                        Step 4 no ipv6 nd managed-config-flag


                        Example:
                        Switch(config)#interface vlan 1
                        Switch(config-if)# no ipv6 nd managed-config-flag
                         

                        Ensures the attached hosts do not use stateful autoconfiguration to obtain addresses.

                         
                        Step 5 no ipv6 nd other-config-flag


                        Example:
                        Switch(config-if)# no ipv6 nd other-config-flag 
                         

                        Ensures the attached hosts do not use stateful autoconfiguration to obtain non-address options from DHCP (domain etc).

                         
                        Step 6 end


                        Example:
                        Switch(config)# end
                         

                        Returns to privileged EXEC mode. Alternatively, you can also press Ctrl-Z to exit global configuration mode.

                         

                        Configuring Stateless Auto Address Configuration With DHCP (CLI)

                        SUMMARY STEPS

                          1.    interface vlan 1

                          2.    ip address fe80::1 link-local

                          3.    ipv6 enable

                          4.    no ipv6 nd managed-config-flag

                          5.    ipv6 nd other-config-flag

                          6.    end


                        DETAILED STEPS
                            Command or Action Purpose
                          Step 1 interface vlan 1


                          Example:
                          Switch(config)# interface vlan 1
                          
                           

                          Creates a interface and enters interface configuration mode.

                           
                          Step 2 ip address fe80::1 link-local


                          Example:
                          Switch(config-if)# ip address 198.51.100.1 255.255.255.0
                             Switch(config-if)# ipv6 address fe80::1 link-local
                             Switch(config-if)# ipv6 address 2001:DB8:0:1:FFFF:1234::5/64 
                             Switch(config-if)# ipv6 address 2001:DB8:0:0:E000::F/64
                           

                          Configures IPv6 address on the interface using the link-local option.

                           
                          Step 3 ipv6 enable


                          Example:
                          Switch(config)# ipv6 enable
                          
                           

                          (Optional) Enables IPv6 on the interface.

                           
                          Step 4 no ipv6 nd managed-config-flag


                          Example:
                          Switch(config)#interface vlan 1
                          Switch(config-if)# no ipv6 nd managed-config-flag
                           

                          Ensures the attached hosts do not use stateful autoconfiguration to obtain addresses.

                           
                          Step 5 ipv6 nd other-config-flag


                          Example:
                          Switch(config-if)# no ipv6 nd other-config-flag 
                           

                          Ensures the attached hosts do not use stateful autoconfiguration to obtain non-address options from DHCP (domain etc).

                           
                          Step 6 end


                          Example:
                          Switch(config)# end
                           

                          Exits from the interface mode.

                           

                          Configuring Stateful DHCP Locally (CLI)

                          This interface configuration is for a Cisco IOS IPv6 router implementing stateful DHCPv6 on a local Switch

                          Before You Begin
                          SUMMARY STEPS

                            1.    configure terminal

                            2.    ipv6 unicast-routing

                            3.    ipv6 dhcp pool IPv6_DHCPPOOL

                            4.    address prefix 2001:DB8:0:1:FFFF:1234::/64

                            5.    dns-server 2001:100:0:1::1

                            6.    domain-name example.com

                            7.    exit

                            8.    interface vlan1

                            9.    description IPv6-DHCP-Stateful

                            10.    ipv6 address 2001:DB8:0:20::1/64

                            11.    ip address 192.168.20.1 255.255.255.0

                            12.    ipv6 nd prefix 2001:db8::/64 no-advertise

                            13.    ipv6 nd managed-config-flag

                            14.    ipv6 nd other-config-flag

                            15.    ipv6 dhcp server IPv6_DHCPPOOL


                          DETAILED STEPS
                              Command or Action Purpose
                            Step 1 configure terminal


                            Example:
                            
                                        
                                      
                            Switch# configure terminal
                            
                            
                             

                            Enters the global configuration mode.

                             
                            Step 2 ipv6 unicast-routing


                            Example:
                            Switch(config)# ipv6 unicast-routing
                             

                            Configures IPv6 for unicasting.

                             
                            Step 3 ipv6 dhcp pool IPv6_DHCPPOOL


                            Example:
                            Switch (config)# ipv6 dhcp pool IPv6_DHCPPOOL
                             

                            Enters the configuration mode and configures the IPv6 DHCP pool on the VLAN.

                             
                            Step 4 address prefix 2001:DB8:0:1:FFFF:1234::/64


                            Example:
                            Switch (config-dhcpv6)# address prefix
                            2001:DB8:0:1:FFFF:1234::/64
                             

                            Specifies the address range to provide in the pool.

                             
                            Step 5 dns-server 2001:100:0:1::1


                            Example:
                            Switch (config-dhcpv6)# dns-server 2001:100:0:1::1
                             

                            Provides the DNS server option to DHCP clients.

                             
                            Step 6 domain-name example.com


                            Example:
                            Switch (config-dhcpv6)# domain-name example.com
                             

                            Provides the domain name option to DHCP clients.

                             
                            Step 7 exit


                            Example:
                            Switch (config-dhcpv6)# exit
                             

                            Returns to the previous mode.

                             
                            Step 8 interface vlan1


                            Example:
                            Switch (config)# interface vlan 1
                             

                            Enters the interface mode to configure the stateful DHCP.

                             
                            Step 9 description IPv6-DHCP-Stateful


                            Example:
                            Switch (config-if)# description IPv6-DHCP-Stateful
                             

                            Enter description for the stateful IPv6 DHCP.

                             
                            Step 10 ipv6 address 2001:DB8:0:20::1/64


                            Example:
                            Switch (config-if)# ipv6 address 2001:DB8:0:20::1/64
                             

                            Enters the IPv6 address for the stateful IPv6 DHCP.

                             
                            Step 11 ip address 192.168.20.1 255.255.255.0


                            Example:
                            Switch (config-if)# ip address 192.168.20.1 255.255.255.0
                             

                            Enters the IPv6 address for the stateful IPv6 DHCP.

                             
                            Step 12 ipv6 nd prefix 2001:db8::/64 no-advertise


                            Example:
                            Switch (config-if)# ipv6 nd prefix 2001:db8::/64
                            no-advertise
                             

                            Configures the IPv6 routing prefix advertisement that must not be advertised.

                             
                            Step 13 ipv6 nd managed-config-flag


                            Example:
                            Switch (config-if)# ipv6 nd managed-config-flag
                             

                            Configures IPv6 interfaces neighbor discovery to allow the hosts to uses DHCP for address configuration.

                             
                            Step 14 ipv6 nd other-config-flag


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

                            Configures IPv6 interfaces neighbor discovery to allow the hosts to uses DHCP for non-address configuration.

                             
                            Step 15 ipv6 dhcp server IPv6_DHCPPOOL


                            Example:
                            Switch (config-if)# ipv6 dhcp server IPv6_DHCPPOOL
                             

                            Configures the DHCP server on the interface.

                             

                            Configuring Stateful DHCP Externally (CLI)

                            This interface configuration is for a Cisco IOS IPv6 router implementing stateful DHCPv6 on an external DHCP server.

                            Before You Begin
                            SUMMARY STEPS

                              1.    configure terminal

                              2.    ipv6 unicast-routing

                              3.    dns-server 2001:100:0:1::1

                              4.    domain-name example.com

                              5.    exit

                              6.    interface vlan1

                              7.    description IPv6-DHCP-Stateful

                              8.    ipv6 address 2001:DB8:0:20::1/64

                              9.    ip address 192.168.20.1 255.255.255.0

                              10.    ipv6 nd prefix 2001:db8::/64 no-advertise

                              11.    ipv6 nd managed-config-flag

                              12.    ipv6 nd other-config-flag

                              13.    ipv6 dhcp_relaydestination 2001:DB8:0:20::2


                            DETAILED STEPS
                                Command or Action Purpose
                              Step 1 configure terminal


                              Example:
                              
                                          
                                        
                              Switch# configure terminal
                              
                              
                               

                              Enters the global configuration mode.

                               
                              Step 2 ipv6 unicast-routing


                              Example:
                              Switch(config)# ipv6 unicast-routing
                               

                              Configures the IPv6 for unicasting.

                               
                              Step 3 dns-server 2001:100:0:1::1


                              Example:
                              Switch (config-dhcpv6)# dns-server 2001:100:0:1::1
                               

                              Provides the DNS server option to DHCP clients.

                               
                              Step 4 domain-name example.com


                              Example:
                              Switch (config-dhcpv6)# domain-name example.com
                               

                              Provides the domain name option to DHCP clients.

                               
                              Step 5 exit


                              Example:
                              Switch (config-dhcpv6)# exit
                               

                              Returns to the previous mode.

                               
                              Step 6 interface vlan1


                              Example:
                              Switch (config)# interface vlan 1
                               

                              Enters the interface mode to configure the stateful DHCP.

                               
                              Step 7 description IPv6-DHCP-Stateful


                              Example:
                              Switch (config-if)# description IPv6-DHCP-Stateful
                               

                              Enter description for the stateful IPv6 DHCP.

                               
                              Step 8 ipv6 address 2001:DB8:0:20::1/64


                              Example:
                              Switch (config-if)# ipv6 address 2001:DB8:0:20::1/64
                               

                              Enters the IPv6 address for the stateful IPv6 DHCP.

                               
                              Step 9 ip address 192.168.20.1 255.255.255.0


                              Example:
                              Switch (config-if)# ip address 192.168.20.1 255.255.255.0
                               

                              Enters the IPv6 address for the stateful IPv6 DHCP.

                               
                              Step 10 ipv6 nd prefix 2001:db8::/64 no-advertise


                              Example:
                              Switch (config-if)# ipv6 nd prefix 2001:db8::/64
                              no-advertise
                               

                              Configures the IPv6 routing prefix advertisement that must not be advertised.

                               
                              Step 11 ipv6 nd managed-config-flag


                              Example:
                              Switch (config-if)# ipv6 nd managed-config-flag
                               

                              Configures IPv6 interfaces neighbor discovery to allow the hosts to uses DHCP for address configuration.

                               
                              Step 12 ipv6 nd other-config-flag


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

                              Configures IPv6 interfaces neighbor discovery to allow the hosts to uses DHCP for non-address configuration.

                               
                              Step 13 ipv6 dhcp_relaydestination 2001:DB8:0:20::2


                              Example:
                              Switch (config-if)# ipv6 dhcp_relay destination 2001:DB8:0:20::2
                               

                              Configures the DHCP server on the interface.

                               

                              Monitoring IPv6 Clients (GUI)

                              To view the IPv6 clients associated with the Switch

                              Before You Begin
                              Select Monitor > Clients

                              The Clients page is displayed. The Clients page contains the following details:

                              • Client MAC Address— Displays the MAC address of the client.
                              • AP Name— Displays the access point name to which the client is connected to.
                              • WLAN— Displays the WLAN associated with the client.
                              • State— Displays the client authentication.
                              • Protocol— Displays the protocol used.

                              To view the client related general details, click the Client MAC Address parameter in the Clients page. The Client > Detail page displays IPv6 addresses of the client under the General tab.


                              Verifying IPv6 Address Learning Configuration

                              This example displays the output of the show ipv6 dhcp pool command. This command displays the IPv6 service configuration on the switch. The vlan 21 configured pool detail displays 6 clients that are currently using addresses from the pool.

                              SUMMARY STEPS

                                1.    show ipv6 dhcp pool


                              DETAILED STEPS
                                  Command or Action Purpose
                                Step 1 show ipv6 dhcp pool


                                Example:
                                Switchshow ipv6 dhcp pool 
                                DHCPv6 pool: vlan21
                                Address allocation prefix: 2001:DB8:0:1:FFFF:1234::/64 valid 86400 preferred 86400 (6 in use, 0 conflicts)
                                DNS server: 2001:100:0:1::1
                                Domain name: example.com
                                Active clients: 6
                                
                                 

                                Displays the IPv6 service configuration on the switch.

                                 

                                Additional References

                                Related Documents

                                Related Topic Document Title
                                IPv6 command reference IPv6 Command Reference (Catalyst 3850 Switches)
                                IP command reference IP Command Reference (Catalyst 3850 Switches)

                                Error Message Decoder

                                Description Link

                                To help you research and resolve system error messages in this release, use the Error Message Decoder tool.

                                https:/​/​www.cisco.com/​cgi-bin/​Support/​Errordecoder/​index.cgi

                                MIBs

                                MIB MIBs Link
                                All supported MIBs for this release.

                                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 website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

                                To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

                                Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

                                http:/​/​www.cisco.com/​support

                                Feature Information for IPv6 Client Address Learning

                                This table lists the features in this module and provides links to specific configuration information:

                                Feature

                                Release

                                Modification

                                IPv6 Client Address Learning Functionality

                                Cisco IOS XE 3.2SE

                                This feature was introduced.