We have problems with the FWSM shun sent by IPS that sometimes they seem to stick in there forever and don't automatically clear. Alot of them are recurring and are positive shuns, but there are a few that shouldn't be shunned and they don't clear!
Which would be best way to send an automatic clear shun to the FWSM!
The shun command lets you block connections from an attacking host. Packets matching the values in the command are dropped and logged until the blocking function is removed manually or by the Cisco IPS sensor.
So you would either have to do it manually or with a script, or the IPS should clear out the shun using the event that triggered it.
I hope it helps.