2.8 SLAAC & DHCPv6

Stateful DHCPv6 Method (Server)

This option is most similar to DHCPv4.In this case, the RA message tells the client to obtain all addressing information from a stateful DHCPv6 server, except the default gateway address which is the source IPv6 link-local address of the RA.

Note: If A Flag=1 and M Flag=1, some operating systems such as Windows will create an IPv6 address using SLAAC and obtain a different address from the stateful DHCPv6 server. In most cases, it is recommended to manually set the A flag to 0.

Stateful DHCPv6 is enabled on a router interface using the ipv6 nd managed-config-flag interface configuration command. This sets the M flag to 1.


Configure Stateful DHCPv6 on an Interface

Enable IPv6 Unicast Routing

R1(config)# ipv6 unicast-routing

Define a DHCPv6 Pool Name

R1(config)# ipv6 dhcp pool [poolname]

Configure Range and Lifetime of Leases

R1(config-dhcpv6)# address prefix [ipv6-address/prefix] lifetime [time]

Define a DNS server

R1(config-dhcpv6)# dns-server [ipv6-address]

Define the domain name

R1(config-dhcpv6)# domain-name [domain]
R1(config-dhcpv6)# exit

Configure IPv6 Addressing on an interface

R1(config)# interface [interface]
R1(config-if)# ipv6 address [ipv6-address]
R1(config-if)# ipv6 address [ipv6-address] link-local

Assign DHCPv6 Stateful Server to the Interface and enable it

R1(config-if)# ipv6 nd managed-config-flag
R1(config-if)# ipv6 nd prefix default no-autoconfig
R1(config-if)# ipv6 dhcp server [poolname]
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)#
Stateful DHCPv6 Complete Configuration example
R1> enable
R1# configure terminal
R1(config)# ipv6 unicast-routing
R1(config)# ipv6 dhcp pool LAN-POOL-1
R1(config-dhcpv6)# address prefix 2001:DB8:CAFE:1::/64 lifetime 1000000
R1(config-dhcpv6)# dns-server 2001:db8:cafe:aaaa:5
R1(config-dhcpv6)# domain-name cisco.com
R1(config-dhcpv6)# exit
R1(config)# interface g0/0
R1(config-if)# ipv6 address 2001:db8:cafe:1::1/64
R1(config-if)# ipv6 address fe80::1 link-local
R1(config-if)# ipv6 nd managed-config-flag
R1(config-if)# ipv6 nd prefix default no-autoconfig
R1(config-if)# ipv6 dhcp server LAN-POOL-1
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)#