Most IPv6 implementation plans make use of both static IPv6 address configuration and dynamic configuration options. As is the case with IPv4, the plan assigns infrastructure devices with static addresses, with client hosts using one of the two dynamic methods for address assignment. IPv6 addressing includes many more options than IPv4, and as a result, many more config-uration options exist. A router interface can be configured with a static global unicast IPv6 address, either with or without using the EUI-64 option. Although less likely, a router could be configured to dynamically learn its IPv6 address with either stateful DHCP or stateless autoconfig. The router interface could be configured to either not use a global unicast address, instead relying solely on its link local address, or to borrow another interface’s address using the IPv6 unnumbered feature. Following Table summarizes the IPv6 configuration commands and their meanings.
|ipv6 address address/length||Static configuration of the entire IPv6 unicast ad- |
|ipv6 address prefix/length eui-64||Static configuration of the first 64 address bits; the |
router derives the last 64 bits with EUI-64.
|ipv6 address autoconfig||Router uses stateless autoconfig to find address.|
|ipv6 address dhcp||Router uses stateful DHCP to find address.|
|ipv6 unnumbered interface-type num- |
|Uses the same IPv6 unicast address as the refer- |
|ipv6 enable||Enables IPv6 on the interface, but results in only a |
link local address.
|ipv6 address address link-local||Overrides the automatically created link local ad- |
dress. The configured value must conform to the
|ipv6 address address/length anycast||Designates that the unicast address is an anycast.|
R2# show running-config
! lines omitted for brevity
ipv6 address 2000:0:0:4::/64 eui-64
ipv6 address 2000:0:0:2::2/64
ipv6 address 2000:0:0:1::/64 eui-64
R2# show ipv6 interface brief
Serial0/0/0 [administratively down/down]
Serial0/1/0 [administratively down/down]
Serial0/1/1 [administratively down/down]