Introduction
As per RFC 4291, a single interface of a router can be configured with multiple IPv6 addresses. All Cisco IOS release with IPv6 support, a router interface can be configured with multiple IPv6 global addresses within the same prefix.
Background
In this document, interface FastEthernet 0/0 of Cisco Router 3745 is configured with multiple IPv6 addressed with command "ipv6 address".
Note: The configuration is tested on Cisco 3745 router running C3745-ADVIPSERVICESK9-M, Version 12.4(25d).
Configuration
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int fa 0/0
R1(config-if)#ipv6 address 2011:ABC1:9:F11::/64 eui-64
R1(config-if)#ipv6 address 2011:ABC1:10:F11::/64 eui-64
R1(config-if)#ipv6 address 2011:ABC1:11:F11::/64 eui-64
R1(config-if)#ipv6 address 2011:ABC1:12:F11::/64 eui-64
Verification
We can verify the IPv6 configuration on the interface by command "show run interface fa 0/0" or by command "show ipv6 interface". Here is an example of the two commands.
R1#sh run int fa 0/0
Building configuration...
Current configuration : 257 bytes
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
ipv6 address 2011:ABC1:9:F11::/64 eui-64
ipv6 address 2011:ABC1:10:F11::/64 eui-64
ipv6 address 2011:ABC1:11:F11::/64 eui-64
ipv6 address 2011:ABC1:12:F11::/64 eui-64
ipv6 enable
end
R1#sh ipv6 int
FastEthernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::C600:13FF:FE68:0
Global unicast address(es):
2011:ABC1:9:F11:C600:13FF:FE68:0, subnet is 2011:ABC1:9:F11::/64 [EUI]
2011:ABC1:10:F11:C600:13FF:FE68:0, subnet is 2011:ABC1:10:F11::/64 [EUI]
2011:ABC1:11:F11:C600:13FF:FE68:0, subnet is 2011:ABC1:11:F11::/64 [EUI]
2011:ABC1:12:F11:C600:13FF:FE68:0, subnet is 2011:ABC1:12:F11::/64 [EUI]
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF68:0
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds
ND advertised reachable time is 0 milliseconds
ND advertised retransmit interval is 0 milliseconds
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
Hosts use stateless autoconfig for addresses.
References
Implementing IPv6 Addressing and Basic Connectivity
