I have 2 DHCP servers, just need 1 to work

September 24, 2011 5:45 PM

I have an Actiontec GT701WG that can supposedly act as a DHCP server, but nothing gets an IP address from it. Manually assigning IP addresses works fine, but that's a pain with several devices. I also have a Linksys WRT54G that I thought I could use as my DHCP server instead, but I can't get it to connect to the Actiontec with the static IP settings. How can I make this work without buying new hardware?

More detail:

The Actiontec has an IP address of 192.168.0.1 and should be auto-assigning IP addresses from 192.168.0.2 to 192.168.0.254. I can connect other devices (e.g. my MacBook) to it by selecting "Using DHCP with manual address" and giving each device an IP in that range. When I set the connection type on the Linksys to Static IP, it gives me more than an IP address to fill in:

Internet IP Address: 192.168.0.55
Subnet Mask: 255.255.255.0 (this is auto-set on other devices)
Gateway: 192.168.0.1
Static DNS 1: 8.8.8.8 (also tried 192.168.0.1)

This doesn't work. Something else I might try?

posted by scottreynen to computers & internet (6 answers total)

Try setting the Actiontec to Transparent Bridged Mode under the WAN IP address settings, and setting the WRT54G to automatically obtain an IP address ("Automatic Configuration - DHCP").
posted by JDHarper at 5:59 PM on September 24, 2011

Just as further explanation: At least on my setup, my router (a Linksys WRT54G2) is responsible for obtaining an IP address from my ISP (so if I go to Static it automatically fills in my external IP address for the "Internet IP Address").

Your Actiontec device appears to be both a modem and a router; we want it to cede the router duties to the WRT54G, which we do by setting it to Bridged Mode.
posted by JDHarper at 6:06 PM on September 24, 2011

If you want to use the Linksys as the dhcp server, you have to manually set its IP address, say to 192.168.0.2. Have it hand out the .1 address as gateway.

Here's the important part - don't use the WAN interface on the Linksys. Connect the Linksys to the Actiontec via a LAN port on each one. This essentially sets the Linksys up as a server and not a router.

That being said, not getting a dhcp address from the Actiontec may mean that it, or your LAN, is interfering with broadcast packets. If this is true, the Linksys won't work as a DHCP server either.

What other devices are on your network besides these two? Any switches/hubs?
posted by bfu at 6:06 PM on September 24, 2011

Changing the Actiontec to Transparent Bridged and the Linksys to DHCP left the Linksys with no IP address (or rather, 0.0.0.0) again. I also tried changing the Linksys to PPPoE (which the Actiontec was previously) with the Actiontec on bridged, and that gave the Linksys an IP address (something outside the 192.168.0.x range), but I still couldn't reach the internet through it.
posted by scottreynen at 7:42 PM on September 24, 2011

Getting the Actiontec back to something I could use with static IPs took about 20 minutes and completely resetting all settings, so I think this modem might just be dying.
posted by scottreynen at 7:47 PM on September 24, 2011

I decided to just buy a new modem.
posted by scottreynen at 1:02 PM on September 25, 2011