Someone showed me a great feature today. One of the constant pains in the network is when you get a port err-disabled on the switch. Regardless of how many times I see it, it always seems to be the last thing I check. There's a little-known feature in the IOS called "err-disable recovery" which automatically turns a err-disabled switchport back on after 5 minutes (by default). The good news is that this command allows you to choose specific reasons where you'd like to re-enable the port, such as re-enabling ports disabled because of a port-flap instance but keeping mac-address security violations error disabled. Here's the syntax to make it happen: