Accessing a bridged DSL modem from behind a Linksys router

Question

I’ve got a pretty standard home network setup that looks like this, starting from the ISP:

• An ISP-provided DSL modem (ActionTec PK5001A if it matters), IP address 192.168.1.1. I followed these instructions to put it in bridge mode.
• A Linksys WRT54GL router, IP address 192.168.1.2. It's connected to the modem through its WAN port and the PC through a LAN port.
• My PC, IP address 192.168.1.95.

Almost everything is working hunky-dory: I can access the Internet just fine. There is just one piece that’s inconvenient, which is that I can’t access the modem from my PC unless I unplug my PC from the router and plug it directly into the modem.

I’m guessing this is because, being a LAN address, the router tries to route it internally; in particular, the router’s routing table looks like this:

Destination       Subnet mask       Gateway           Interface
207.225. 84. 51   255.255.255.255     0.  0.  0.  0   WAN
192.168.  1.  0   255.255.255.  0     0.  0.  0.  0   LAN & Wireless
  0.  0.  0.  0     0.  0.  0.  0   207.225. 84. 51   WAN

I thought I might be able to fix this by adding a route for destination 192.168.1.1, subnet 255.255.255.255 (I only want to change the route for exactly this IP), gateway 0.0.0.0 on the WAN interface. However, when I try to add that route, the router pops up an error message saying only “Invalid static route!.”

Why is this route invalid? How can I access my modem from my PC without shifting my Ethernet cable from the router to the modem?

There is an existing question that seems quite similar; however, it was marked as a duplicate of a question that no longer appears to exist, so there is no longer an answer to that question.

Answer 1

By far the simplest solution is to move your modem or your LAN to a different subnet.

Eg:

• Modem: 192.168.1.1
• Router: 192.168.2.1

Then it wont have the modem as part of the DHCP pool and will treat it as a remote network (all remote networks go via the same port withe a “router on a stick”).

It’s not uncommon for modems to change over to 192.168.100.1 or similar when bridging for this very reason.

Answer 2

I think, the problem is that you try to create the static route to 192.168.1.1 destination through the port with address 207.225.84.51.

First you should assign to your WAN port IP-address from the 192.168.1.0 subnet or another address; but then you must also change the modem IP. But you can do this only if your router’s firmware supports PPPoE (or another protocol, used by your ISP) with Dual Access (sometimes also called “Russian PPPoE”, “Russian PPTP” etc.). If so, you’d be able to configure router WAN IP separate from the address received by PPPoE connection. Then it would be no problem to create the static route to your modem.

If the official Linksys firmware for this router does not supports Dual Access connections, then you can change firmware to Tomato or DD-WRT, they both supports it.

Update. Also you can first try to change LAN IP of your router to IP from another range, e.g. 192.168.10.1.