Help: Linux router connected to AP via wifi
 

Hi, I've got a bit of a (hopefully not too) tricky question here. My current setup is thus:

Gentoo box/router connected (via ethernet cable) to wireless AP, and then the rest of my home network connects to the AP via their wifi cards and through that receives their internet access, dhcp, etc. This is all working near flawlessly.

What I'd like to do is thus:

Move the access point to a more central location in my house connected to another computer that isn't the router to improve the wifi signal strength to the rooms out the back. Also still share the internet connection from my gentoo box but now via the wifi card in it.

I've got a Netgear WPN311 wifi card installed in my gentoo box, and the driver installed and working (it can get an IP from dhcp via the wireless link, so I'm assuming that's a good indicator that it's working). My problem arises when I move the AP (or disconnect it from the ethernet port on the gentoo box). When I move it, I lose all connectivity with it. Pinging it I get 3/4 packets can't reach the other end, and the other one I never hear from again.

When I switch on another PC on the network to try get an IP wirelessly, it doesn't receive an IP. Now watching tcpdump on the wifi link (ath0 I think it's called - being an Atheros chipset and all), I can see traffic coming from the MAC of the PC I've switched on, but it doesn't send the DHCP address back to it, and there is also no mention of a DHCP request in /var/log/messages like usual.

Any suggestions for what I can try would be greatly appreciated.

Can post any logs etc later if needed.

I'm trying something a bit more standard now, and still getting a similar result - setting up the wifi card in my gentoo box in master mode, and then setting the real AP to be a repeater. Other machines in the house can see the wireless network from the gentoo box fine (for the time being leaving the real AP out of it to avoid complexity), and connect to the wireless network, but when it goes to get an IP via DHCP, the request doesn't get through. I'm thinking it could be my firewall blocking packets from coming in via the wifi port as when I run "tcpcump -i ath0", it can see the DHCP packets coming in, but there's no record of them appearing in /var/log/messages - could that sound right?

When I close the tcpdump (ctrl+c), it says

x packets captured
y packets received by filter
0 packets dropped by kernel

(where x and y vary depending how long I let it run for).