NIM subnet mismatch and LED 613

Here's something that can occur fairly easily: we changed the IP address of a NIM client to another subnet, but forgot to update the client's subnet on the NIM server, i.e. 'lsnim -l <client>' still showed the old subnet. Then we did a BOS install on the client, and right after loading the kernel the client got stuck in LED 613 ('8 mm 80 GB VXA-2 tape device'). Of course, the LED's meaning has nothing to do with the original problem, so this is one of those "better-write-that-down" things.