Connecting Two OSPF Areas With Stub Area In Middle - Quick Solution & Verification

Here is quick solution and verification for my last post: BTW are you not in love with GRE tunnels still ? 
:-)


http://deepakarora1984.blogspot.com/2010/12/connecting-two-ospf-areas-with-stub.html


R1#sh ip ro | b ^G
Gateway of last resort is not set


     11.0.0.0/32 is subnetted, 1 subnets
C       11.11.11.11 is directly connected, Loopback0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0




R2#sh ip ro | b ^G
Gateway of last resort is 12.12.12.1 to network 0.0.0.0


     33.0.0.0/32 is subnetted, 1 subnets
O       33.33.33.33 [110/2] via 23.23.23.3, 00:01:19, FastEthernet1/0
     23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, FastEthernet1/0
     11.0.0.0/32 is subnetted, 1 subnets
O IA    11.11.11.11 [110/2] via 12.12.12.1, 00:01:19, FastEthernet0/0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*IA 0.0.0.0/0 [110/2] via 12.12.12.1, 00:01:19, FastEthernet0/0




R3#sh ip ro | b ^G
Gateway of last resort is not set


     33.0.0.0/24 is subnetted, 1 subnets
C       33.33.33.0 is directly connected, Loopback0
     23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, FastEthernet0/0
====================================================


R1(config)#router ospf 1
R1(config-router)#area 1 virtual-link 255.255.255.2
% OSPF: Area 0.0.0.1 is a stub or nssa so virtual links are not allowed
R1(config-router)#

====================================================

R1(config)#int tu 1

R1(config-if)#ip add 112.112.112.1 255.255.255.0

R1(config-if)#tu so f0/0

R1(config-if)#tu dest 12.12.12.2 

R1(config-if)#exit

R2(config)#int tu 1

R2(config-if)#ip add 112.112.112.2 255.255.255.0

R2(config-if)#tu so f0/0

R2(config-if)#tu dest 12.12.12.1

R2(config-if)#exit

*Mar  1 00:19:34.695: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to up

====================================================

R1(config)#router ospf 1

R1(config-router)#net 112.112.112.1 0.0.0.0 a 0

R1(config-router)#exit

R2(config)#router ospf 1

R2(config-router)#net 112.112.112.2 0.0.0.0 a 0

R2(config-router)#exit

====================================================

R1#sh ip ro | b ^G

Gateway of last resort is not set

     33.0.0.0/32 is subnetted, 1 subnets

O IA    33.33.33.33 [110/11113] via 112.112.112.2, 00:01:35, Tunnel1

     23.0.0.0/24 is subnetted, 1 subnets

O IA    23.23.23.0 [110/11112] via 112.112.112.2, 00:01:35, Tunnel1

     112.0.0.0/24 is subnetted, 1 subnets

C       112.112.112.0 is directly connected, Tunnel1

     11.0.0.0/32 is subnetted, 1 subnets

C       11.11.11.11 is directly connected, Loopback0

     12.0.0.0/24 is subnetted, 1 subnets

C       12.12.12.0 is directly connected, FastEthernet0/0

R1#ping 33.33.33.33 so lo0

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 33.33.33.33, timeout is 2 seconds:

Packet sent with a source address of 11.11.11.11 

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/17/40 ms

R1#trace 33.33.33.33 so lo0

Type escape sequence to abort.

Tracing the route to 33.33.33.33

  1 112.112.112.2 4 msec 4 msec 4 msec

  2 23.23.23.3 12 msec *  24 msec

HTH...

Deepak Arora