Switch Underruns

[mallenson]

I'm seeing switch underruns climb slowly on a 3548 XL switch with about 35 servers on it all running 100 / Full Duplex (Auto dedected) on same VLAN. No other large amount of errors exist, except that output buffer failures equal overruns.

Switch utilization is at about 65-70% or a little less, memory is OK.

Switch appears overutilzed as underruns keep increasing, but I don't understand why?

Can you tune switch buffers to componsate?

[robho]

The XL switch architecture has a shared memory architecture. There is no way to fine tune it. If possible, run the "less important" servers at 10/half to reduce overall utilization of the switch. Or, decide on a switch upgrade --> 3750 :)

RH

[glen.grant]

Yeah that is running pretty hard , have never seen running above 35-40 % . This is an older model and the backplane capacity is nearly as high as the newer models and if you have 35 servers running on this thing it's chance it is overloaded .