I am getting errors in ospf and iam not able to isolate problem. Please find config below
eth0 area 2
s1 area 1
router ID: address of eth0
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 22.214.171.124, Ethernet0
here 126.96.36.199 is ip of s2 interface of R2.
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.
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 188.8.131.52. 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 184.108.40.206?
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 220.127.116.11, Ethernet0
The router generating this message received an invalid OSPF packet on Ethernet 0 from neighbor 18.104.22.168. 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.
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.
Your topology is a little confusing. Can you confirm whether my understanding is correct. You have two routers and 4 areas:
22.214.171.124/24 -- area 0
126.96.36.199/24 -- area 10
188.8.131.52/24 -- area 10
184.108.40.206/24 -- area 1
220.127.116.11/24 -- 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 18.104.22.168 that has a different area ID tag instead of area 2. Make sure the network 22.214.171.124/24 is part of area 2 on both devices.
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.
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 126.96.36.199. I think this is the cause of the error. comments are apreciated. Thanks