OSPF - no Inter-area Route List

[aconticisco]

Hi,

set 3 routers with the one in the middle having a couple of interfaces connected to the respective ospf areas (area 1 and area 0).

The problem is that I am not getting any Inter-area routes even though the middle router has all routes to each network in both areas listed.

Any idea why the Inter-area Routes (area 1 in this example) are not listed as I expect that any routers in area 0 receive these right?

Thanks

[Rolf Fischer]

Hi,

could you please share

• the OSPF configs of all the three routers (the section under 'router ospf <process-id>')
• the output of 'show ip ospf border-routers' from the non-ABRs
• the output of 'show ip ospf neighbor' from the ABR

HTH
Rolf

[aconticisco]

Hi Rolf,

R1

router ospf 1

log-adjacency-changes

network 0.0.0.0 255.255.255.255 area 1

R2

ip ospf priority 2

ip ospf priority 2

router ospf 1

log-adjacency-changes

network 192.168.1.0 0.0.0.255 area 1

router ospf 10

log-adjacency-changes

network 192.168.2.0 0.0.0.255 area 0

R3

router ospf 10

log-adjacency-changes

network 0.0.0.0 255.255.255.255 area 0

R3#show ip ospf border-routers

OSPF Process 10 internal Routing Table Codes: i - Intra-area route, I - Inter-area route

R1#show ip ospf border-routers

OSPF Process 1 internal Routing Table Codes: i - Intra-area route, I - Inter-area route

R2

Neighbor ID Pri State Dead Time Address Interface

3.3.3.3 1 FULL/BDR 00:00:34 192.168.2.2 FastEthernet1/0

1.1.1.1 1 FULL/BDR 00:00:36 192.168.1.2 FastEthernet0/0

Thanks

[Rolf Fischer · Accepted solution]

Thanks for the additional information.

The two processes on R2 are "ships in the night", there is no interaction between them (unless you configure redistribution, but that's not what you want I guess). So R2 is not an ABR, as you can see in the output of 'show ip ospf border-router' as well. R2 has two independent Link State Databases: R1-R2 (PID 1) and R2-R3 (PID 10), just as if two different routing protocols were running on R2.

So you have to delete one of the processes on R2 and add the missing network-statement under the other process. A PID (process ID) is locally significant (doesn't have to match among neighbors), you don't need to change it on R1 or R3.

HTH
Rolf

[aconticisco]

perfect Rolf

removed process 10 from R2 and advertised network 192.168.2.0 0.0.0.255 area 0 using process 1 and it works.

For some reason I was relating multiple areas to multiple process but clearly you identified that one process is needed per router irrespective if there is one or multiple areas.

Thanks

[Rolf Fischer]

You're welcome. Thanks for using the rating system.

FYI: The typical scenario for the use of several OSPF processes is when a router has more than one routing context (VRF / VRF-Lite).

Only in few cases it can be necessary to redistribute among 2 processes in the same routing-context: 4170 - OSPF Redistribution Among Different OSPF Processes