On R1, R2, R3, R4 and R7

R1#sh run | b ipv
ipv6 unicast-routing
!
!
!
interface Ethernet0/1
 no ip address
 half-duplex
 ipv6 address 2005:0:104::1/64
 ipv6 address FE80::1 link-local
!
interface Serial0/1
 no ip address
 ipv6 address 2005:0:102::1/64
 ipv6 address FE80::1 link-local
 clock rate 64000
!


R3#sh run int s 1/0
Building configuration...

Current configuration : 233 bytes
!
interface Serial1/0
 no ip address
 encapsulation frame-relay
 ipv6 address 2005:0:237::3/64
 ipv6 address FE80::3 link-local
 frame-relay map ipv6 2005:0:237::2 302 broadcast
 frame-relay map ipv6 2005:0:237::7 307 broadcast
end