So if you ever find yourself with a Cisco Aironet 1142 wireless access point that does not pass DHCP info to wireless clients, check your port security first where the access point is plugged in. Somehow, after a power outage, the port security on the Cisco ESW540-24P got flipped to “Locked” with a limit of 3. This was driving me mad until I got a clue in an old support forum post. Flipping this back to “Unlocked” was the instant fix.
I’d better save this config…