IPv6 Manually Configured Tunnel Configuration

Sample IPv6 Tunnel Network

IPv6 tunnels are configured on domain border routers that communicate with each other through an IPv4 network.

Manually Configured Tunnel Configuration on RT1 and RT2:

RT1:
!
ipv6 unicast-routing
!
interface FastEthernet1/0
 ipv6 address 2345:6789:AAAA:11::1/64
 ipv6 rip tunnel-ripng enable
!
interface Serial0/0
 ip address 10.10.10.1 255.255.255.252
!
interface Tunnel0
 ipv6 address 2001:1111:1111:1111::1/64
 tunnel source Serial0/0
 tunnel destination 10.10.10.2
 tunnel mode ipv6ip
 ipv6 rip tunnel-ripng enable
!
======================================================================
RT2:
!
ipv6 unicast-routing
!
interface FastEthernet1/0
 ipv6 address 2345:6789:AAAA:22::1/64
 ipv6 rip tunnel-ripng enable
!
interface Serial0/0
 ip address 10.10.10.2 255.255.255.252
!
interface Tunnel0
 ipv6 address 2001:1111:1111:1111::2/64
 tunnel source Serial0/0
 tunnel destination 10.10.10.1
 tunnel mode ipv6ip
 ipv6 rip tunnel-ripng enable
!

After an IPv6 tunnel is created between the domain border routers, traffic need to be routed between the sites. This can be achieved using static routes or a dynamic routing protocol. Below shows that the route to the IPv6 network behind RT2 is learnt via RIPng:

RT1#sh ipv6 route
IPv6 Routing Table - 7 entries
Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP
       U - Per-user Static route
       I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary
       O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2
C   2001:1111:1111:1111::/64 [0/0]
     via ::, Tunnel0
L   2001:1111:1111:1111::1/128 [0/0]
     via ::, Tunnel0
C   2345:6789:AAAA:11::/64 [0/0]
     via ::, FastEthernet1/0
L   2345:6789:AAAA:11::1/128 [0/0]
     via ::, FastEthernet1/0
R   2345:6789:AAAA:22::/64 [120/2]
     via FE80::A0A:A02, Tunnel0
L   FE80::/10 [0/0]
     via ::, Null0
L   FF00::/8 [0/0]
     via ::, Null0
RT1#

Note: The phrase manually configured tunnels refers to an RFC standard encapsulation of IPv6 inside IPv4 packets. There is no formal name for this feature; most documents refer to it as manual tunnels, manual overlay tunnels, configured tunnels, or manually configured tunnels.