[c-nsp] Catalyst 3750 stacks with many members

[Dale Shaw]

Hi all,

We have a few large (>6 member) cat3750 stacks in our environment,
most in L2 edge/access roles, and most providing PoE to cisco IP
phones.

Does anyone have any tips as to how to make large stacks more
reliable? We're seeing really high CPU and have found you need to be
really careful doing anything that has the potential to swamp the CPU
-- the other day I crashed a stack master by clearing the CDP
neighbour table (a bit silly in hindsight, given the number of CDP
table entries [phones], but I was troubleshooting a stale neighbour
problem).

Does changing to the 'VLANs' SDM template for switch stacks in this
role make any difference? These stacks don't do any routing, or
traffic ACLs.

We've tried 12.2(40)SE, 12.2(44)SE2 and 12.2(44)SE3. Our biggest stack
is 7 members. You're supposed to be able to stack 9 of these things
(and I don't recall reading about any caveats), so it's a bit
concerning. Disabling certain functionality (e.g. CDP) to stabilise is
one thing, but long term it would be nice if it 'just worked'.

cheers,
Dale