I have a modem/router, Netgear DG834, and a wireless access point (AP), Netgear WG602. The AP is directly connected to the router.

My old working configuration was:

Router IP address      : 192.168.0.1 
Access point IP address: 192.168.0.10

My new configuration is:

Router IP address      : 192.168.1.1 
Access point IP address: ???.???.???.???

I changed my router's IP address/LAN settings to set up a VPN with another Netgear router that had the same LAN configuration.

The wireless network is still up and perfectly working, but I can't find the AP's IP address. I've tried broadcast ping but the AP won't respond. I looked at the router "attached devices", but it's not there. I've played around with Nmap and arp request but the AP is totally invisible.

I can fix it by resetting it to factory settings, but I'm very interested in learning more about this problem. I'm also interested in network security and this fact of having an invisible AP well, it's something I'd like to understand.