[j-nsp] EX series - LACP flapping during ethernet storm.

[Felix Schueren]

Tim,

> 
> Anyone encountered anything like this before?  Any ways to mitigate?
> 

I feel your pain. The EXes have a very, very, very weak link between
routing & forwarding engine (hardcoded to a limit of 1,000 pps). I don't
know if they've finally gotten around to it, but as of a year or so ago
they did not even have priority queues for that, so IS-IS/BGP/OSPF
sessions were dropped due to ARPs between end user stations etc.

Your best bet is likely to impose a very very hard broadcast storm
control setting to your customers using
set ethernet-switching-options storm-control interface <x> bandwidth
500k (experiment during next flood ;))

Or set the broadcast limit even lower (I think 100k is the lowest
possible) and add no-unknown-unicast under storm-control, as the regular
ethernet flooding should not be a problem for the EXes.

The biggest problem is with "router alert" style traffic (i.e., most
broadcasts or all-nodes multicast etc), if that gets looped the EX will
soon start dropping control protocol traffic, losing BFD/LACP/IS-IS
adjacencies etc.

Kind regard,

Felix

-- 
Felix Schüren
Head of Network

-----------------------------------------------------------------------
Host Europe GmbH - http://www.hosteurope.de
Welserstraße 14 - 51149 Köln - Germany
Telefon: 0800 467 8387 - Fax: +49 180 5 66 3233 (*)
HRB 28495 Amtsgericht Köln - USt-IdNr.: DE187370678
Geschäftsführer: Patrick Pulvermüller, Thomas Vollrath

(*) 0,14 EUR/Min. aus dem dt. Festnetz; maximal 0,42 EUR/Min. aus
den dt. Mobilfunknetzen