[c-nsp] 6500: another eompls problem

[Liviu Pislaru]

hello,

first of all, i think the error "INTERFACE_API-4-TBLERROR"
doesn't have anything in common with "SPANTREE-2-RECV_PVID_ERR";

because you use different VLANs at the ends of the EoMPLS tunnel and
the BPDUs with vlan id 812 are encapsulated through the EoMPLS tunnel
and decapsulated in vlan 4093, the port of the next switch that connects to
Port-channel23.4093 will be put in STP bloking state and the end-to-end
traffic will fail even if the EoMPLS tunnel is still UP.

when you get "Apr 19 20:03:29.356 MSD: %SPANTREE-2-RECV_PVID_ERR:
Received BPDU with inconsistent peer vlan id 812 on Port-channel23 VLAN4093"
go to the switches that connects to Po42.812 and Po23.4023 and type:
"sh spanning-tree blockedports" and you will see the port in STP blocking 
state.

One workaround is to use the same VLANs on both ends.

The second is to use "spanning-tree bpdufilter enable" on Port-channel ports 
(on PE)
or to disable spanning-tree on PE, but be sure your topology is l2 loop 
free.

If your topology permits to establish port-based EoMPLS or VLAN based (with 
SVI)
with the clients directlly connected to the PE, this will be the third 
workaround.

I'm sure there are others config tricks that you can use but i've only 
tested the three above.

--
liviu.


----- Original Message ----- 
From: "Alexandre Snarskii" <snar at paranoia.ru>
To: "Cisco-NSP Mailing List" <cisco-nsp at puck.nether.net>
Sent: Thursday, April 19, 2007 7:32 PM
Subject: [c-nsp] 6500: another eompls problem


>
> Hi!
>
> Router in question is 6500, IOS 12.2(33)SRA1.
>
> We have a plenty of mux-uni eompls vc's, configured just "by the book":
>
> interface Port-channel42.812
> encapsulation dot1Q 812
> xconnect XX.XXX.XXX.XX 812 encapsulation mpls
>
> Today, while adding another one,
>
> interface Port-channel23.4093
> encapsulation dot1Q 4093
> xconnect XX.XXX.XXX.XX 4093 encapsulation mpls
>
> we faced strange problem:
>
> a) New vc got blocked by spanning-tree on far side of etherchannel:
>
> Apr 19 20:03:29.356 MSD: %SPANTREE-2-RECV_PVID_ERR: Received BPDU with 
> inconsistent peer vlan id 812 on Port-channel23 VLAN4093.
>
> b) Even worse: old vc (812) stopped functioning - while we saw 
> mac-addresses
> from downstream on switch, terminating Portchannel42, but no mac-addresses
> were learned from eompls side.. Instead, we saw packets which should
> be forwarded to vc 812 (po42.812) appeared on vc 4093 (po23.4093)..
>
> Well, after deleting new vc, and re-creating old one (no int po42.812/
> int po42.812) everything returned back to work. But, next try to
> configure new vc failed with the same reason..
>
> Interesting note: when deleting new vc (no int po42.4093) next message
> appeared in log:
> Apr 19 20:03:54.321 MSD: %INTERFACE_API-4-TBLERROR: A error occurred while 
> using the Index Table utility for Element Deletion.
> -Traceback= 41B38B88 41B41B04 41B4C3AC 404B7D74 404D964C 40F9B78C 40F9B778
>
> So, i'm suppose that there is some another bug..
>
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