P2p *PVID_Inc and Port VLAN ID Mismatch

[Alex49]

Hi to all,

normally this is a native VLAN mismatch behavior.

A customer has connected some 3COM switches to a VSS and some of them, not all, show this error message and block two vlans

The configuration is ok. We have only trunk ports and the 3Com are single home connected

Oct  7 23:25:04.673 MET: %SPANTREE-SW1-2-RECV_PVID_ERR: Received BPDU with inconsistent peer vlan id 130 on GigabitEthernet1/1/35 VLAN1.

Oct  7 23:25:04.673 MET: %SPANTREE-SW1-2-BLOCK_PVID_PEER: Blocking GigabitEthernet1/1/35 on VLAN0130. Inconsistent peer vlan.

sh spanning-tree inconsistentports

Name                 Interface                 Inconsistency

-------------------- ------------------------- ------------------

VLAN0001             GigabitEthernet1/1/34     Port VLAN ID Mismatch

VLAN0001             GigabitEthernet1/1/35     Port VLAN ID Mismatch

VLAN0001             GigabitEthernet2/1/41     Port VLAN ID Mismatch

VLAN0001             GigabitEthernet2/1/42     Port VLAN ID Mismatch

VLAN0130             GigabitEthernet1/1/34     Port VLAN ID Mismatch

VLAN0130             GigabitEthernet1/1/35     Port VLAN ID Mismatch

VLAN0130             GigabitEthernet2/1/41     Port VLAN ID Mismatch

VLAN0130             GigabitEthernet2/1/42     Port VLAN ID Mismatch

Thanks in advance

Alex

[Sandeep Choudhary]

HI Alex,

Looks to me like the native VLAN ID's are configured differently on  interfaces. It has been to same at both ends of the trunk interface.  Have a look at it. Hopefully, should fix up. Do let me know.

Change the native VLAN on SW1 (gigbitethernet1/1/35)connection to .....

Here is the document to troubleshoot these kind of inconsistencies.

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00801d11a0.shtml

Regards

Hope it helps.

[Rolf Fischer · Accepted solution]

Hi Alex,

the problem is that the 3com switches do not recognize the Cisco proprietary SSTP BPDUs for the per-VLAN spanning-tree instances. Instead, they are flooded by the 3coms, following the rules of multicast. So the 3com switches act like virtual trunks and the BPDUs are forwarded to other Cisco switches (the other VSS member in your scenario).

Here you can find another discussion about this with more details: https://supportforums.cisco.com/message/4012602

HTH

Rolf

[Alex49]

Hi fischer.rolf

thanks for the hint. I think this is the problem we have.

Regards

Alex

[Alex49]

Hi sandeepchoudhary21

thanks for answering. I know there is a vlan mismatch. But it is strange, because the config is ok and only some of the

access switches makes trouble.

Regards

Alex