2.8 SLAAC & DHCPv6

Stateful DHCPv6 Method (Client)

A router can also be a DHCPv6 client. The client router needs to have ipv6 unicast-routing enabled and an IPv6 link-local address to send and receive IPv6 messages.


There are five steps to configure and verify a router as a stateless DHCPv6 client

  1. Enable IPv6 Unicast Routing
  2. Configure the client router to create an LLA
  3. Configure the client router to use DHCPv6
  4. Verify that the client router is assigned a GUA
  5. Verify that the client router received other necessary DHCPv6 information

Configure Stateful DHCPv6 on an Interface

1. Enable IPv6 Unicast Routing

R1(config)# ipv6 unicast-routing

2. Configure the client router to create an LLA

R1(config)# interface [interface] 
R1(config-if)# ipv6 enable 

3. Configure the client router to use DHCPv6

R1(config-if)# ipv6 address dhcp 
R1(config-if)# exit 
R1#

4. Verify that the client router is assigned a GUA

R1# show ipv6 interface brief 
GigabitEthernet0/0/0 [up/up] 
  unassigned 
GigabitEthernet0/0/1 [up/up] 
  FE80::2FC:BAFF:FE94:29B1 
  2001:DB8:ACAD:1:B4CB:25FA:3C9:747C
Serial0/1/0 [up/up] 
  unassigned 
Serial0/1/1 [up/up] 
  unassigned 
R1#

5. Verify that the client router received other necessary DHCPv6 information

R1# show ipv6 dhcp [interface]
GigabitEthernet0/0/1 is in client mode 
  Prefix State is IDLE 
  Address State is OPEN 
  Renew for address will be sent in 11:56:33 
  List of known servers: 
    Reachable via address: FE80::1 
    DUID: 000300017079B3923640 
    Preference: 0 
    Configuration parameters: 
      IA NA: IA ID 0x00060001, T1 43200, T2 69120 
      Address: 2001:DB8:ACAD:1:B4CB:25FA:3C9:747C/128
              preferred lifetime 86400, valid lifetime 172800 
              expires at Sep 29 2019 11:52 AM (172593 seconds)
      DNS server: 2001:4860:4860::8888 
      Domain name: example.com 
      Information refresh time: 0 
  Prefix Rapid-Commit: disabled 
  Address Rapid-Commit: disabled 
R1#
(CLIENT) Stateful DHCPv6 Complete Configuration example
R1> enable
R1# configure terminal
R1(config)# ipv6 unicast-routing
R1(config)# interface interface g0/0/1
R1(config-if)# ipv6 enable
R1(config-if)# ipv6 address dhcp
R1(config-if)# exit
R1#

R1# show ipv6 interface brief
GigabitEthernet0/0/0 [up/up]
  unassigned
GigabitEthernet0/0/1 [up/up]
  FE80::2FC:BAFF:FE94:29B1
  2001:DB8:ACAD:1:B4CB:25FA:3C9:747C
Serial0/1/0 [up/up]
  unassigned
Serial0/1/1 [up/up]
  unassigned
R1#

R1# show ipv6 dhcp [interface]
GigabitEthernet0/0/1 is in client mode
  Prefix State is IDLE
  Address State is OPEN
  Renew for address will be sent in 11:56:33
  List of known servers:
    Reachable via address: FE80::1
    DUID: 000300017079B3923640
    Preference: 0
    Configuration parameters:
      IA NA: IA ID 0x00060001, T1 43200, T2 69120
      Address: 2001:DB8:ACAD:1:B4CB:25FA:3C9:747C/128
              preferred lifetime 86400, valid lifetime 172800
              expires at Sep 29 2019 11:52 AM (172593 seconds)
      DNS server: 2001:4860:4860::8888
      Domain name: example.com
      Information refresh time: 0
  Prefix Rapid-Commit: disabled
  Address Rapid-Commit: disabled
R1#