IPv6: Tunnelling over IPv4: Tunnel mode: ipv6ip

IPv6: Tunnelling over IPv4: Tunnel mode: ipv6ip

·         Let me take a small topology to configure IPV6 tunneling over IPv4.

·         OSPFv3 is configured between R1 & R2 and R3 & R4

·         IPv4 is configured between R2-R3

·         If I need to connect R1 and R4’s IPv6 network, then I need to tunnel the IPv6 traffic through IPv4.

 

Configs:

 

R1#show run int fa0/0

Building configuration...

 

Current configuration : 134 bytes

!

interface FastEthernet0/0

 no ip address

 duplex auto

 speed auto

 ipv6 address 2001:12::1/64

 ipv6 enable

 ipv6 ospf 1 area 0

end

 

R1#show run int loop0

Building configuration...

 

Current configuration : 89 bytes

!

interface Loopback0

 no ip address

 ipv6 address 2001:1::1/64

 ipv6 ospf 1 area 0

end

 

R1#

 

R2(config-if)#do show run int fa0/0

Building configuration...

 

Current configuration : 134 bytes

!

interface FastEthernet0/0

 no ip address

 duplex auto

 speed auto

 ipv6 address 2001:12::2/64

 ipv6 enable

 ipv6 ospf 1 area 0

end

 

R2(config-if)#

 

R1#show ipv6 ospf neighbor

 

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface

2.2.2.2           1   FULL/DR         00:00:38    4               FastEthernet0/0

R1#

 

R2(config-if)#do show ipv6 ospf nei

 

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface

1.1.1.1           1   FULL/BDR        00:00:38    4               FastEthernet0/0

R2(config-if)#

 

R3(config-if)#do show run int fa0/0

Building configuration...

 

Current configuration : 121 bytes

!

interface FastEthernet0/0

 no ip address

 duplex auto

 speed auto

 ipv6 address 2001:34::3/64

 ipv6 ospf 1 area 0

end

 

R3(config-if)#

 

R4#show run int fa0/0

Building configuration...

 

Current configuration : 121 bytes

!

interface FastEthernet0/0

 no ip address

 duplex auto

 speed auto

 ipv6 address 2001:34::4/64

 ipv6 ospf 1 area 0

end

 

R4#show run int loop0

Building configuration...

 

Current configuration : 89 bytes

!

interface Loopback0

 no ip address

 ipv6 address 2001:4::4/64

 ipv6 ospf 1 area 0

end

 

R4#

 

R3(config-if)#do show ipv6 ospf nei

 

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface

4.4.4.4           1   FULL/DR         00:00:38    4               FastEthernet0/0

R3(config-if)#

 

R4#show ipv6 ospf nei

 

Neighbor ID     Pri   State           Dead Time   Interface ID    Interface

3.3.3.3           1   FULL/BDR        00:00:31    4               FastEthernet0/0

R4#

 

Observation:

·         OSPFv3 is up between R1-R2 and R3-R4

 

·         Let me create tunnel through IPv4 to send IPv6 traffic

·         I’m going to use IPV6iIP mode for the tunnel

·         IPV6IP mode uses protocol number 41 for transporting.

 

R2(config-if)#do show run int tun1

Building configuration...

 

Current configuration : 139 bytes

!

interface Tunnel1

 no ip address

 ipv6 address 2001:23::2/64

 tunnel source 2.2.2.2

 tunnel destination 3.3.3.3

 tunnel mode ipv6ip

end

 

R2(config-if)#

 

R3(config-if)#do show run int tun1

Building configuration...

 

Current configuration : 139 bytes

!

interface Tunnel1

 no ip address

 ipv6 address 2001:23::3/64

 tunnel source 3.3.3.3

 tunnel destination 2.2.2.2

 tunnel mode ipv6ip

end

 

R3(config-if)#

 

R2#show ipv6 int tun1

Tunnel1 is up, line protocol is up

  IPv6 is enabled, link-local address is FE80::202:202

  Global unicast address(es):

    2001:23::2, subnet is 2001:23::/64

  Joined group address(es):

    FF02::1

    FF02::2

    FF02::1:FF00:2

    FF02::1:FF02:202

  MTU is 1480 bytes

  ICMP error messages limited to one every 100 milliseconds

  ICMP redirects are enabled

  ND DAD is enabled, number of DAD attempts: 1

  ND reachable time is 30000 milliseconds

  Hosts use stateless autoconfig for addresses.

R2#

 

R3#show ipv6 int tun1

Tunnel1 is up, line protocol is up

  IPv6 is enabled, link-local address is FE80::303:303

  Global unicast address(es):

    2001:23::3, subnet is 2001:23::/64

  Joined group address(es):

    FF02::1

    FF02::2

    FF02::1:FF00:3

    FF02::1:FF03:303

  MTU is 1480 bytes

  ICMP error messages limited to one every 100 milliseconds

  ICMP redirects are enabled

  ND DAD is enabled, number of DAD attempts: 1

  ND reachable time is 30000 milliseconds

  Hosts use stateless autoconfig for addresses.

R3#

 

Observation:

·         Tunnel is up between R2 and R3

·         Now, let me advertise the tunnel interfaces into OSPFv3 on R2 and R3

 

R2(config)#int tunnel 1

R2(config-if)#ipv6 ospf 1 area 0

R2(config-if)#

R2(config-if)#

*Mar  1 08:58:33.053: %OSPFv3-5-ADJCHG: Process 1, Nbr 3.3.3.3 on Tunnel1 from LOADING to FULL, Loading Done

R2(config-if)#

 

R3(config)#int tunnel 1

R3(config-if)#ipv6 ospf 1 area 0

R3(config-if)#

*Mar  1 03:53:55.127: %OSPFv3-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Tunnel1 from LOADING to FULL, Loading Done

R3(config-if)#

 

·         Now, let me see R1 and R4 IPV6 routing tables:

 

R1#show ipv6 route

IPv6 Routing Table - 9 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   2001:1::/64 [0/0]

     via ::, Loopback0

L   2001:1::1/128 [0/0]

     via ::, Loopback0

O   2001:4::4/128 [110/11131]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

C   2001:12::/64 [0/0]

     via ::, FastEthernet0/0

L   2001:12::1/128 [0/0]

     via ::, FastEthernet0/0

O   2001:23::/64 [110/11121]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

O   2001:34::/64 [110/11131]

     via FE80::C001:25FF:FE30:0, FastEthernet0/0

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R1#

 

R4#show ipv6 route

IPv6 Routing Table - 9 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

O   2001:1::1/128 [110/11131]

     via FE80::C003:25FF:FE30:0, FastEthernet0/0

C   2001:4::/64 [0/0]

     via ::, Loopback0

L   2001:4::4/128 [0/0]

     via ::, Loopback0

O   2001:12::/64 [110/11131]

     via FE80::C003:25FF:FE30:0, FastEthernet0/0

O   2001:23::/64 [110/11121]

     via FE80::C003:25FF:FE30:0, FastEthernet0/0

C   2001:34::/64 [0/0]

     via ::, FastEthernet0/0

L   2001:34::4/128 [0/0]

     via ::, FastEthernet0/0

L   FE80::/10 [0/0]

     via ::, Null0

L   FF00::/8 [0/0]

     via ::, Null0

R4#

 

R1#ping 2001:4::4

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2001:4::4, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 12/35/96 ms

R1#

 

R4#ping 2001:1::1

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 2001:1::1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 12/27/64 ms

R4#