[c-nsp] Cisco 7204 CPU utilisation.

[Alex Balashov]

Greetings,

I have a 7204 with a FastEthernet interface that has a few 
point-subinterfaces for inter-VLAN routing, and at its peak pushes about 
25 mbps, most of it inter-VLAN traffic.

Naturally, a Layer 3 switch is a smarter idea than a big Layer 3 VLAN 
router-on-a-trunk-stick these days, but the budget isn't there right now.

When the traffic peaks at ~25 mbps, there's quite a bit of CPU 
utilisation;  as much as 60%.  I was wondering if there are any tips on 
what I can do to optimise the forwarding.  One idea was to put in a GigE 
card (the subject of another thread), but I do not expect this will 
actually impact anything CPU-bound since all of that traverses the 
backplane and engine.  I also enabled fast route-caching and a number of 
other fairly obvious things, but those types of optimisations are what 
got me down to ~60% at peak in the first place - without the 
route-caching it was choking at nearly full utilisation.

Any other common best practises?

Cheers,

-- Alex

-- 
Alex Balashov
Evariste Systems
Web    : http://www.evaristesys.com/
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