[c-nsp] Solution to %SPANTREE-2-RECV_PVID_ERR, except disable spanning tree?

[Benjamin.Conconi at nok.ch]

We had a similar problem a time ago. We did some tests with a cisco es20
linecard and eompls services. This card has a feature called
vlan-translation were you can translate one vlan to a other. So we had a
setup like this


|-----|            |-------|            |-----|
|2960 |--Vlan 2412-|Eompls |--Vlan 2413-|2960 |
|-----|            |-------|            |-----|

The problem is, that the PVSTP couples the vlan id with the bridge
priority. Means if you let your bridge priority by default, the bridge
priority of vlan 2412 is 32768 + 2412 = 35180. Hence the bridge priority
of vlan 2413 is 35181. You can verify this with the command sh
spanning-tree.

Both, the bridge priority and the vlan id are integrated in the bpdu of
the pvstp algorithm. If the left-hand switch sends a bpdu to the eompls
core, the vlan id 2412 will be translated to 2413, but the bridge
priority remains. Because the bridge priority and the vlan id are
coupled by a simple addition, the right-hand switch (2960) detects, that
something changed the vlan id. The Switch will then block the vlan and
it apperas with the message you got:

>> %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking GigabitEthernet1/0/25 on
>> VLAN2413. Inconsistent local vlan

So, I would mean it is the fault of your service provider rather than
yours.

Regards,
Benjamin Conconi



On Mon, Jun 02, 2008 at 09:34:10PM -0600, Clinton Work wrote:
>
> I think that you need to speak with your service provider.  Based upon

> the error message it looks like vlan 2412 at site #1 is connected to  
> vlan 2413 at site #2. There was a post six to 12 months ago on the
same  
> topic and it was a service provider issue. 

I don't think the provider has got a bad configuration, partly
because we have spoken with them about this several times and
partly because of what I didn't include below, that we have the
same problem for every vlan they gave us (30 in all, 6 each to
5 locations). As long as we only use one vlan to each location,
everything works. When we add another vlan to one of the locations,
all 6 vlans to that location goes into blocking mode because of the
errors below. It could possibly be a systematic error somewhere.

> STP to L2 FTTx gear:
> http://puck.nether.net/pipermail/cisco-nsp/2008-January/046310.html

Great thread on the subject. I hadn't seen that, I will read it and
check for ideas.

Many thanks!

Peter Olsson

>
> Clinton. 
>
> Peter Olsson wrote:
>> Two offices have a cisco 3750 each. They connect via a
>> bridged fastethernet service, on non-cisco equipment,
>> which offers six vlans on the line. When the 3750 only
>> allow one vlan on the switch port toward the line,
>> everything works fine.
>>
>> When we try to add another allowed vlan, we get this error
>> and both vlans block:
>> %SPANTREE-2-RECV_PVID_ERR: Received BPDU with inconsistent peer
>> vlan id 2412 on GigabitEthernet1/0/25 VLAN2413.
>> %SPANTREE-2-BLOCK_PVID_LOCAL: Blocking GigabitEthernet1/0/25 on
>> VLAN2413. Inconsistent local vlan.
>> %SPANTREE-2-BLOCK_PVID_PEER: Blocking GigabitEthernet1/0/25 on
>> VLAN2412. Inconsistent peer vlan.
>>
>>
>>
>>   
>
>
> -- 
> =======================================================
> Clinton Work
> Airdrie, AB
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