John R Pierce wrote:
I don't actually think my motives are relevant.
In case I didn't described the situation clearly, my CentOS server is connected to an ADSL modem by ethernet (eth0). The modem's IP address is 192.168.1.254 .
your goal is very relevant if youj are expecting us to suggest a workable solution.
My point was that you suggested various alternatives to what I was aiming at. There is a perfectly simple "solution", which is actually what I am doing now, namely to attach the router to the modem. But as I said, I am hoping for a solution where all data will pass through my server.
but ouch, sounds like your modem is ALSO a NAT router, and is probably running DHCP already. what IP is eth0 of this linux PC ?
The server currently has IP address 192.168.1.2, and the modem has IP address 192.168.1.254.
assuming I'm right, and your modem is in fact doing NAT routing too, then I'd put DD-WRT or Tomato opensource firmware on the WRT54GL, configure it for LAN only use, so all 5 ports are LAN, plug it into the modem, plug your computer(s) into the WRT's switch also, and configure the WRT"s wireless. now all your systems will be on that 192.168.1.xxx subnet.
Can one actually have two NICs on a computer in the same LAN? I would have thought that would cause problems?