Extreme Packet Loss 6509

Unanswered Question

Hi we have a 6509 running 12.2(17d)SXB11 with a strange error

A LES 100mb circuit is plugged into port gi4/48 L3 (copper) when utilisation of this hits 100% it causes extreme packet loss on ports gi1/48 and gi1/41 which are completely un-realted (one is another LES circuit 100mb copper L3 link and one is to a server in the same room 1000mb L2).

has anyone ever experienced anything like this before? I guess it could be a hardware fault but all reports and logs show no fault.

Thanks in advance

I have this problem too.
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Giuseppe Larosa Thu, 01/15/2009 - 04:51

Hello Jonathan,

depending on the line card model groups of ports share some hardware resources (ASIC chips).

In your case may be groups of 8 ports of the same 48 GE 10/100/1000 linecard use the same ASIC.

This could explain the relation between ports g1/48 and g1/41

Hope to help


Giuseppe Larosa Thu, 01/15/2009 - 14:30

Hello Jason,

>> also why would performance on module 4 effect module 1?

I took the two ports as being on the same linecard !

Sorry for this, they should be unrelated but I see you are doing some form of circuit emulation what do you mean with LES ?

this can create a link between the ports the feature may allocate buffers or queues that are shared and when one link is full other frames wait to be transmitted filling these resources. (just a guess)

Hope to help



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