Loosing PING responses on your 53xx and 41xx network ?

[Arjan van de Velde]

(and maybe more packets?)

In our configuration (2*5308xl end 2*4108gl, linked in a circular way with FEC trunks), we experienced the loss of PING reponses. End2End network traces confirmed that packets just disappears in the switch(es), DROP cq. error counters were not updated !
The idea was to bring back the trunk type to TRUNK, but this was not enough.
After upgrading the switch versions to E.10.02 and G.07.70 for resp. 5308 and 4108 did solve the problem.
I have read a lot of threads concerning this problem, I hope this solution can help you.

[André Beck]

Hi,

Not 5308xl but between 3400cl and 4108gl. Or *maybe*, the packets go some L2 hops, an L3 hop, further L2 hops and then reach the system in question, and back it is the same (though routing turns out to be asymmetric, the way back is different). I do have a Trunk (the dumb sort, didn't see a reason to run FEC with no Cisco involved) between the two, but finding out where packets actually get lost is still not trivial. The system in question is found "unreachable" quite often by Insight Manager, but I'm not yet sure it is the trunk, I rather fear it is the 10G CX4 ISL between two 3400cl. This link even shows a high rate of receive errors. I've just deployed some static host routes on the end system which, due to lucky topology specifics, cause the packets to avoid the 10G. Now I'm monitoring packet loss and there was none so far.

Seems I really should open that ticket on the 10Gs now...