[c-nsp] arp timeout issues

[Ed Butler]

Fairly standard set up; stack of 3750s running OSPF to 6500s. On the
3750s there are a number of SVIs, with "arp timeout 300" set on them.
The same VLANs have a MAC againg time of 5 minutes too.

The behaviour we are seeing is that every six minutes (not 5) traffic to
a host on the SVI will die for 500ms or so, and this coincides with the
ARP entry being refreshed. CPU usage on the 3750 stack averages 15-20%.

We have a number of similar set up that don't replicate this problem.
Has anyone seen similar and can recommend a course of action? Hopefully
something more sophisiticated than simply increasing the ARP timeout!

Regards,

Ed Butler
RapidSwitch Ltd
DDI: 020 7106 0731

RapidSwitch Ltd, Sovereign House, 227 Marsh Wall, London, E14 9SD

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