[j-nsp] Juniper and Cisco - BGP MPLS L2VPN VPLS interoperability

Adam Vitkovsky Adam.Vitkovsky at gamma.co.uk
Mon Nov 23 18:54:38 EST 2015

Hi Aaron,

> From: Aaron [mailto:aaron1 at gvtc.com]
> Sent: Monday, November 23, 2015 7:58 PM
> I then enabled bgp mpls l2vpn, and BAMMO !  now listen closely... this
> brought down about 20 other bgp neighbor sessions with 20 different cisco
> me3600's all over my network .  now please, listen closely again, we aren't
> talking about an initial bgp session renegotiation, from this point forward the
> ME3600's were not able to reestablish their bgp sessions at all !
Are the 20 different me3600's configured with l2vpn AF please?
Are the two RRs configured with l2vpn AF please?
Have you see the sessions bouncing on the me3600's
Are you running code past 15.3(1)S that should be capable of BGP Enhanced Attribute Error Handling but now I'm not that sure if MEs do support it,

This really looks like the second case I mentioned where RRs relied an UPDATE message that ME3600's perceived as malformed cause they could not parse through it.
And either BGP enhanced error handling wasn't enabled or a mandatory attribute was affected they ought to reset the session over which such a malformed UPDATE message is received.
Once the session is re-established they receive the update again and reset the session again -so the whole process loops.
And only stops after the culprit attribute is removed from the update message.

> I did "rollback 1" on the juniper 5048 and 104 and finally the me3600's were
> able to settle down and establish bgp neighboring with the dual RR core and
> all is well.


        Adam Vitkovsky
        IP Engineer

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E:      Adam.Vitkovsky at gamma.co.uk
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