About 18 months ago when we first rolled out the network, on firmware 4.3, we used to experience problems with SM going to sleep and requiring a reboot.

There was some issue the bridge timeout on the SM’s and the CISCO switch arp time out setting, so we set the UDP timeout to 4min and the arp to 1min. The switches that connect to our backend the arp timeout is 4 hours.

Trying to reduce the arp traffic on our network, we tried moving the arp to 2 min but i’ve been told that the SM seems to go to sleep after a few days and requires either a reboot or unplug/plug of cable.

any ideas/advice on what should be the optimum settings ?

I had the same issue a few years ago. I went all out and set the Bridge Timeout to 1440 minutes (24 hours) on all radios on the network. I have not had a problem since.

our bridge timeout is 1440 by default…

but we still have an arp timeout of 1 sec on the SM’s, what is your arp timeout for the NAT enabled SM’s and also what is the arp timeout on your switches/routers in your core network.