08-31-2011 07:53 PM - edited 03-07-2019 01:59 AM
Hi,
My router generate an ospf invalid packet, ( Router A and B are generating these log ).
%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from x.x.x.x (router C IP address) vlan xx
show ip ospf interface on each directly connected interface ( A to ABR and c to ABR ) resulting a same ospf area,
Any suggestion or advise why these log shows up? i don't use virtual links and as far as i know there's no routing issue / problem happen.
08-31-2011 07:58 PM
Hello Daniel,
This looks as if you assigned the links from A to ABR and from B to ABR to the area 1 only in the A/B configuration, but on ABR routers, these links are still assigned to area 0. Please verify that using the command
show ip ospf interface brief
on both ABRs - watch for the Area column in the output. Both ABRs must report the links to A and B being also placed into area 1.
Best regards,
Peter
08-31-2011 08:12 PM
Hi Peter,
thanks for your reply, i've verified both links from router a/b to ABR and ABR to a/b is on the same area,
here is the output
ROUTER A
router-A#sh ip ospf int b
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Vl232 1 12 10.204.14.34/30 10 BDR 1/1
ROUTER B
router-B#sh ip ospf int b
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Vl332 1 12 10.204.15.34/30 10 BDR 1/1
ABR A
ABR-A#sh ip ospf int vl232
Vlan232 is up, line protocol is up
Internet Address 10.204.14.33/30, Area 12
ABR B
ABR-B#sh ip ospf int vl 332
Vlan332 is up, line protocol is up
Internet Address 10.204.15.33/30, Area 12
08-31-2011 09:44 PM
Daniel,
Thank you for keeping me informed.
This is interesting. Note that the ABRs appear to have a successful peerings with A and B according to the F/C column. The show ip ospf neighbor on router A and B should hence confirm a successful adjacency of A and B to ABRs.
I had a closer look at the message you provided:
%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from x.x.x.x (router C IP address) vlan xx
This is interesting. Routers A and B can see OSPF Hello packets from router C. This looks like the ABRs are actually switching the packets from C to A and B, or somehow, the OSPF Hello packets from router C are leaking to A and B. Do you have a common VLAN that spans from A/B through ABRs to C? That would explain this phenomenon.
Best regards,
Peter
09-01-2011 12:45 AM
Hi Peter,
Just to make things more clear, These is the logs i've seen on router A and B
%OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 10.204.34.17, Vlan111
I did some checking whether vlan 111 also span to C
router-A# sh ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Vl232 1 12 10.204.14.34/30 10 BDR 1/1
Vl111 1 12 10.204.1.8/24 400 DR 1/1
router-A#sh vlan id 111
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
111 VLAN0111 active Gi0/1, Gi0/2, Gi0/3, Gi0/4, Gi0/5, Gi0/8, Gi0/12
router-C# sh vlan id 111
VLAN 111 not found in current VLAN database
vlan 111 is not spanned to router C , but i find it on router-ABR-A
router-ABR-A#sh vlan id 111
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
111 VLAN0111 active Po17
router-ABR-A#sh cdp ne po17 d
-------------------------
Device ID: *****************
Entry address(es):
IP address: 10.204.40.242
router-ABR-A#sh run | b er os
router ospf 1
router-id 10.204.12.91
log-adjacency-changes
auto-cost reference-bandwidth 10000
network 10.204.40.240 0.0.0.7 area 0
ABR-A assigned vlan 111 to area 0, is this what causing the logs on router A,B ?
09-01-2011 01:04 AM
Hello,
I am somewhat at loss seeing the diverse router ID's without knowing what exactly they refer to, but according to what you have commented, it seems that both router A and ABR-A have interface Vlan111 configured, and while A has this interface put into area 12, ABR-A has this interface in area 0, resulting in area mismatch.
However, if I am to believe that the error message displayed on A refers to the IP address of C, not ABR-A, as you originally indicated, then it still must be the Vlan111 being simply trunked over ABR-A towards switch C.
Seeing your logical topology, i.e. what VLANs exist and how the routers are interconnected by them, would be helpful.
Best regards,
Peter
09-01-2011 04:30 AM
Entry address(es):
IP address: 10.204.40.242
router-ABR-A#sh run | b er os
router ospf 1
router-id 10.204.12.91
log-adjacency-changes
auto-cost reference-bandwidth 10000
network 10.204.40.240 0.0.0.7 area 0
ABR-A assigned vlan 111 to area 0, is this what causing the logs on router A,B ?
Hi,
If this network(10.204.40.240 0.0.0.7) is not in area 0, this could cause the problem. But this router C address in the error message is a bit strange.
Regards,
Alex
09-01-2011 04:50 AM
Hello,
Would you mind posting the sanitized config of all the switches/routers involved?
Regards,
Bruno Silva.
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