Lucent GBE (4 x VC4) clues needed

Saku Ytti saku+nanog at
Sat Oct 21 11:03:12 UTC 2006

On (2007-09-21 16:12 +0300), Saku Ytti wrote:

> (oops technical question in nanog, wearing my asbestos suit)
> Consider this topology
> GSR - 3750 --(GE over 4xVC4) - NSE100 - NSE100 --(GE over 4xVC4) -- 3550 - GSR

This should have been Nortel GBE, not Lucent my bad.

Anyhow, just wanted for sake of archive report that it's the Nortel
4xVC4 that corrupts packets, it mostly seems to corrupt source MAC
and always same bits, that is, any L2 will learn mostly same MAC with
few different vendor codes, we can also see this in wireshark on
fibresplitter. (It's not limited strictly to source MAC, but it's
not random by any means)
It's not broken hardware (unless by design), as it can be seen in both of
the production legs and we've recreated the same problem in lab.
Most likely software issue in Nortel.


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