IPv6 Tunneling over IPv4

interface Loopback0
 ip address 1.1.1.1 255.255.255.255
 ip ospf 10 area 0

!
interface Ethernet0/0
 ip address 172.16.10.1 255.255.255.252
 ip ospf 10 area 0

router ospf 10

R2#

interface Ethernet0/0
 ip address 172.16.10.2 255.255.255.252
 ip ospf 10 area 0
!
interface Ethernet0/1
 ip address 172.16.20.2 255.255.255.252
 ip ospf 10 area 0

router ospf 10

interface Loopback0
 ip address 3.3.3.3 255.255.255.255
 ip ospf 10 area 0
!
interface Ethernet0/0
 ip address 172.16.20.1 255.255.255.252
 ip ospf 10 area 0
!
router ospf 10

interface Tunnel0
 no ip address
 tunnel source Loopback0
 tunnel destination 1.1.1.1

interface Tunnel0
 no ip address
 tunnel source Loopback0
 tunnel destination 3.3.3.3

interface Tunnel0
 ipv6 enable
 ipv6 ospf 20 area 0

R3#show ipv6 ospf neighbor
            OSPFv3 Router with ID (3.3.3.3) (Process ID 20)

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface
1.1.1.1           0   FULL/  -        00:00:36    10              Tunnel0


R3#show ipv6 ospf interface
Tunnel0 is up, line protocol is up
  Link Local Address FE80::A8BB:CCFF:FE01:3000, Interface ID 11
  Area 0, Process ID 20, Instance ID 0, Router ID 3.3.3.3
  Network Type POINT_TO_POINT, Cost: 1000
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    Hello due in 00:00:06
  Graceful restart helper support enabled
  Index 1/1/1, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 2, maximum is 3
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 1.1.1.1
  Suppress hello for 0 neighbor(s)

interface Loopback1
 no ip address
 ipv6 address 2001::1/64
 ipv6 enable
 ipv6 ospf 20 area 0
end

interface Loopback1
 no ip address
 ipv6 address 2003::3/64
 ipv6 enable
 ipv6 ospf 20 area 0
end

R1#show ipv6 route
IPv6 Routing Table - default - 4 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
       B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
       H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
       IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
       ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
       O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
       ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, la - LISP alt
       lr - LISP site-registrations, ld - LISP dyn-eid, a - Application
C   2001::/64 [0/0]
     via Loopback1, directly connected
L   2001::1/128 [0/0]
     via Loopback1, receive
O   2003::3/128 [110/1000]
     via FE80::A8BB:CCFF:FE01:3000, Tunnel0
L   FF00::/8 [0/0]
     via Null0, receive


R1#ping 2003::3
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2003::3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms