ospf error OSPF-4-ERRRCV

[malikasim]

Hello,

I am getting errors in ospf and iam not able to isolate problem. Please find config below

R1 :

eth0 area 2

s1 area 1

router ID: address of eth0

R2:

s1 area1

s2 area 0

I configured virtual link between R1 and R2. and Iam getting these console errors continuously on R1

00:13:34: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 151.20.1.3, Ethernet0

here 151.20.1.3 is ip of s2 interface of R2.

Any suggestions?

[Richard Burts]

Asim

You have given some details, but not enough for us to really identify the problem. If you would post the configuration of the interfaces and of OSPF on both routers it would give us better information to work with. It would also be helpful to have the output of show ip ospf from both routers.

HTH

Rick

[malikasim]

Please find the config of both routers attached.

Thanks

[Richard Burts]

Asim

I am having a little confusion since your original post identified routers as R1 and R2 but the configuration files that you posted both routers are called R3. However I have looked at the config files and have the following comments and question:

- the configuration of the virtual link looks ok.

- I am somewhat puzzled by the fact that the non-backbone router has 2 virtual links configured. Is there a reason for that?

- it looks to me like the virtual link is working - especially when the non-backbone router identifies itself as an ABR (which means that it considers itself to be a member of the backbone). And it is especially interesting that the non-backbone router says that it has 2 interfaces in area 0. I consider this indication that the virtual link is working.

- the address mentioned in the error message is 151.20.1.3. This address is not on either of the routers that you have shown us. What router is it on - and is that router also configured to do virtual link? Can you post the config of the router that has 151.20.1.3?

HTH

Rick

[smothuku]

Hi ,

The following is the description of error message which you are getting on the router.

Problem - Mismatched Area ID

%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area

must be virtual-link but not found from 151.20.1.3, Ethernet0

The router generating this message received an invalid OSPF packet on Ethernet 0 from neighbor 151.20.1.3. The packet is invalid because its area ID is area 0 (the backbone area). This implies that the receiving router's Ethernet 0 interface is not in area 0. Note that the neighboring router, which has its interface in area 0, won't display this message in its console logs. Only the router whose interface is in an area other than area 0 generates the error message.

Solution

To avoid these messages, make sure that both sides have the same area ID by checking the network statement under OSPF in the router configuration. For example, if the link 10.10.10.0/24 between two routers should be in area 1, make sure the network statement on both routers includes this particular link in area 1. The network command on both routers would look like this:

router ospf 1

network 10.10.10.0 0.0.0.255 area 1

The following link is very useful and it may help you in resolving the problem.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094819.shtml

Thanks,

Satish

[malikasim]

Thnaks satish but I have already read these articles. still the pbm is unresolved.

[sundar.palaniappan]

Your topology is a little confusing. Can you confirm whether my understanding is correct. You have two routers and 4 areas:

R1:

151.20.1.0/24 -- area 0

151.20.6.0/24 -- area 10

R2:

151.20.6.0/24 -- area 10

130.10.2.0/24 -- area 1

130.10.4.0/24 -- area 2 via E0

By virtue of the virtual link R2 becomes an ABR and the routes are getting exchanged successfully as verified by you in the attachments. The OSPF error you are getting is due to the fact R2 is getting hello packets on E0 from a device with IP address 151.20.1.3 that has a different area ID tag instead of area 2. Make sure the network 130.10.4.0/24 is part of area 2 on both devices.

HTH

Sundar

[malikasim]

Iam attaching complete scenario and config files of all routers are also attached. Hope this clarifies issue.

Sumdar thanks for suggestion but 4.0 network is ethernet network on company A r3 router and I think it should be part of area 2 only on r3.

[sundar.palaniappan]

I presume your network connectivity is good and your only concern is the invalid packet error you are getting on R3. You aren't forming any OSPF adjacency via E0 and the only reason why have E0 part of area 2 is because you want that network to be advertised via OSPF. If that's the case, then configure 'passive interface e0' under the router ospf mode and the network would continue to be advertised but you should stop getting the error messages.

HTH

Sundar

[malikasim]

Hello,

I will not be able to test this as I am not able

to access the lab for some reason. But while investigating the configuration I found that the virtual link on R5 is incorrectly configured and

It should point to 151.20.2.2. I think this is the cause of the error. comments are apreciated. Thanks