Enabling IPv6 Routing and Assigning Addresses
RouterA#configure terminal
RouterA(config)#ipv6 unicast-routing
RouterA(config)#interface fastethernet0/0
RouterA(config-if)#description Local LAN
RouterA(config-if)#ipv6 address 4001:0:1:1::2/64
RouterA(config-if)#interface serial 1/0
RouterA(config-if)#description point-to-point line to Internet
RouterA(config-if)#ipv6 address 4001:0:1:5::1/64