Why doesn't my Airport show the names of my devices?

Episode 1114 (1:19:03)

Chris from Miami, FL
Apple Airport Express

Chris bought a fourth Airport Express, but now the wireless client is broadcasting the Wi-Fi information by numbers, not names. So he has no clue what devices are what. He says it happened after upgrading the software. Leo says that's baffling, but he has a hunch it's the device's MAC addresses.

The chatroom says that the ARC table is full. Leo also recommends rebooting and resetting the router to clear that out. But since Chris has done that, it can't be the ARC table. So this is a mystery. Leo says that it's normal not to see names in that table. The Time Capsule is in Bridge mode, and it can only see the MAC address. So he would have to look in the DHCP (dynamic host configuration protocol). Two devices running in DHCP can make it even worse. Chris should put one in bridge mode. Only one router should be in DHCP mode.