Guys
I am facing a strange issue with below topology in OSPF: The same has been
posted on internetworkexpert forum (http://ieoc.com/forums/t/8231.aspx) but
as usual no reply by anyone so I am posting this problem here as well , hope
someone help.
(R1 s0/0)------*AREA 0* ------------s0/0 (R2 F0/1)----------------*AREA 1-*
----------(F0/1 R3)-----------*AREA 2*----------- (R4)
192.168.12.0/24
192.168.24.0/24
As you can see that R4 is not connected to backbone router therefore it is
require virtual link or tunnel.
for this configuration , I used tunnel to configure between R2 and R3
Below is the config :-
R2 -
interface Tunnel0
ip address 22.22.22.22 255.255.255.0
ip ospf network broadcast
tunnel source 192.168.23.2
tunnel destination 192.168.23.3
end
R3
interface Tunnel0
ip address 33.33.33.33 255.255.255.0
ip ospf network broadcast
tunnel source 192.168.23.3
tunnel destination 192.168.23.2
end
The 22.22.22.22 and 33.33.33.33 has been advertise into (tunnel IP) AREA 0 :
R2#sh run | sec router ospf
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 2.2.2.2 0.0.0.0 area 1
network 22.22.22.22 0.0.0.0 area 0
network 192.168.12.2 0.0.0.0 area 0
network 192.168.23.2 0.0.0.0 area 1
Now the issue is that , I am able to ping 22.22.22.22 address from router R3
but not able to do ping 33.33.33.33
from R2 , The tunnel is up both end side.
if I check the ospf database on R2 for network 33.33.33.0/24 , you can see
that it is there in database but
not in routing table as ROUTING BIT IS NOT SET
R2#show ip ospf database sum 33.33.33.0
OSPF Router with ID (2.2.2.2) (Process ID 1)
Summary Net Link States (Area 1)
LS age: 48
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 33.33.33.0 (summary Network Number)
Advertising Router: 3.3.3.3
LS Seq Number: 80000005
Checksum: 0xD2A
Length: 28
Network Mask: /24
TOS: 0 Metric: 11111
TOS: 0 Metric: 11111
if you do same command on R3 for network 22.22.22.0 then :-
R3#show ip ospf database sum 22.22.22.0
OSPF Router with ID (3.3.3.3) (Process ID 1)
Summary Net Link States (Area 1)
Routing Bit Set on this LSA <---- NOTE
LS age: 1471
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 22.22.22.0 (summary Network Number)
Advertising Router: 2.2.2.2
LS Seq Number: 80000007
Checksum: 0xB4A5
Length: 28
Network Mask: /24
TOS: 0 Metric: 11111
You can see that routing bit set for 22.22.22.0 on R3 and it is there in
routing table. I can ping this network
Ping Test :-
R2#ping 33.33.33.33
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 33.33.33.33, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R2#
R2#
R2#show ip route 33.33.33.33
% Network not in table
R3#ping 22.22.22.22
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.22.22.22, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/40/80 ms
R3#
R3#show ip route 22.22.22.22
Routing entry for 22.22.22.0/24
Known via "ospf 1", distance 110, metric 11112, type inter area
Last update from 192.168.23.2 on FastEthernet1/0, 00:17:55 ago
Routing Descriptor Blocks:
* 192.168.23.2, from 2.2.2.2, 00:17:55 ago, via FastEthernet1/0
Route metric is 11112, traffic share count is 1
The another thing is that if I shutdown serial interface S0/0 of R2 then I
am able to ping 33.33.33.33 network , The S0/0 is touch to backbone area
(area 0)
R2#config t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#int s0/0
R2(config-if)#shut
R2(config-if)#
*Mar 1 02:09:46.111: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Serial0/0
from F
ULL to DOWN, Neighbor Down: Interface down or detached
*Mar 1 02:09:48.095: %LINK-5-CHANGED: Interface Serial0/0, changed state to
adm
inistratively down
*Mar 1 02:09:49.095: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Serial0/0,
changed state to down
R2(config-if)#
R2(config-if)#
R2(config-if)#
R2(config-if)#end
R2#
R2#
R2#ping 33.33.33.33
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 33.33.33.33, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/36/116 ms
R2#
R2#
R2#show ip ospf database sum 33.33.33.0
OSPF Router with ID (2.2.2.2) (Process ID 1)
Summary Net Link States (Area 1)
Routing Bit Set on this LSA (<--- Now routing bit set)
LS age: 1980
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 33.33.33.0 (summary Network Number)
Advertising Router: 3.3.3.3
LS Seq Number: 80000004
Checksum: 0xF29
Length: 28
Network Mask: /24
TOS: 0 Metric: 11111
Regards
Amit Chopra
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