[c-nsp] Low activity systems lose net connectivity

[Phil Mayers]

Tauren Mills wrote:
> Phil,
> 
> Thanks for the suggestion.  However, changing the arp timeout to 300
> doesn't seem to have helped.

Hmm. Re-reading your email, it doesn't sound like that was the problem 
anyway.

Can you supply more detail on the physical topo? Does the router hang 
off the switch on only one physical port? Are you using subinterfaces on 
the router (and corresponding vlans on the switch)?

If it takes as little as 15 seconds for quiet servers to fall off the 
network, then logically something rapid is happening that's breaking 
their connectivity.

Is is possible you've got an inter-vlan loop or similar and the mac 
addresses in the FDB are flip-flopping between the real ports and the 
port with the loop? Or maybe a device with proxy arp enabled which is 
stealing the IP addresses of the valid servers?

Get a server into the failed state then do a:

sh ip arp <macaddress>

...on the router for the clients MAC address and a:

sh mac-address-table address <macaddress>

...on the switch.