R1#sh run | b interface Eth
!
interface Ethernet0/1
 no ip address
 half-duplex
 ipv6 address 2005:0:104::/64 eui-64
 ipv6 rip R1Rip enable
!
interface Serial0/1
 no ip address
 ipv6 address 2005:0:102::/64 eui-64
 ipv6 rip R1Rip enable
 clock rate 64000



R2#
interface Serial1/1
 no ip address
 ipv6 address 2005:0:102::/64 eui-64
 ipv6 rip R2Rip enable
!

R4#sh run | b interface Loo
interface Loopback0
 no ip address
 ipv6 address 2000:4:4::/64 eui-64
 ipv6 rip R4Rip enable
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
 ipv6 address 2005:0:104::/64 eui-64
 ipv6 rip R4Rip enable
!