Can't find a wireless access point's IP address after changing router IP/LAN settings

Question

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.

Answer 1

The access point's IP address is probably still 192.168.0.10, since you didn't change it. That makes it unreachable by IP. Normally, an access point only has an IP address for configuration purposes, so with an IP address that's unreachable, you probably can't configure it. Data will still pass through it just fine though.

If you temporarily assign a PC connected to the access point an additional IP address that can reach the AP, such as 192.168.0.55, you can then reach the AP on its old IP address. That should allow you to correct the IP address to one that is inside the new LAN address range.

Answer 2

Run

arp -a 

and you will get all the IPs and corresponding MAC addresses. You need to check the corresponding MAC address on the network, but nmap tells witch one is the AP.

Answer 3

Using nmap, you can do a ping sweep - many devices won't respond to a broadcast ping, so this will ping each device individually.

nmap -sP 192.168.1.1-255

Answer 4

Is your Wireless AP configured for HCP or have the static IP address. If it is having the static Ip address then the Ip will remain same 192.168.0.1. Connect the Wireless Ap to a PC providing ip 192.168.0.2 and gateway 192.168.0.1. From the PC ping the ip 192.168.0.1 and as I also faced the same problem you can find it.

If it is configured for DHCP then you have to guess the Ip address only.