Accessing Modem Configuration

[neve]

I just upgraded from Tomato on a WET54GL to Merlin's firmware (374.41) on a RT-AC56U.
One of the problems I'm having is getting to my cable modem's configuration page.

Tomato had a Route Modem IP option and I used to be able to go to http://192.168.100.1 to access the modem's configuration.

Is there something similar in Merlin's firmware, and if not, could someone advise me how I can get to my Modem's configuration without physically moving cables around?

This seems like a fundamental configuration step so I'm surprised my searching didn't turn up any definitive instructions on how to accomplish this.

My LAN is set up as 192.168.1.*
Netstat seems to tell me that the Router's WAN address is 10.196.1.10

 

[Martineau]

I just upgraded from Tomato on a WET54GL to Merlin's firmware (374.41) on a RT-AC56U.
One of the problems I'm having is getting to my cable modem's configuration page.

Tomato had a Route Modem IP option and I used to be able to go to http://192.168.100.1 to access the modem's configuration.

Is there something similar in Merlin's firmware, and if not, could someone advise me how I can get to my Modem's configuration without physically moving cables around?

This seems like a fundamental configuration step so I'm surprised my searching didn't turn up any definitive instructions on how to accomplish this.

My LAN is set up as 192.168.1.*
Netstat seems to tell me that the Router's WAN address is 10.196.1.10

Search using 'modem subnet' returns....

http://forums.smallnetbuilder.com/showthread.php?t=11957

NOTE: I have found that not all modems in bridge mode can be accessed using this technique, but TP-Link modems did - can't recall if my Zoom did etc.

Regards,

 

[neve]

Thanks

I had seen that, but was wondering if there was a way to do it though the GUI. I followed truva's instructions and got it working.

I'll paste the instructions truva posted here (with some clarifications) in case it might help someone else.

If you are using Merlin's firmware, here is a definitely working way of accessing modem interface through the router:

1. Give your modem an IP that is outside the router's ip range. (In my case the Router was on 192.168.1.* and the modem was on 192.168.100.*).

2. Enable jffs partition. (under Administration)

3. You need to add two scripts to the /jffs/scripts directory, namely wan-start and nat-start scripts. (I did this by using SSH to get a prompt and vi to create the file).


wan-start script (Assigns an IP on the Modems subnet to the WAN port):

#!/bin/sh
ifconfig `nvram get wan0_ifname`:0 192.168.0.2 netmask 255.255.255.0

Note : the IP number shown in bold must be one more than your modem's IP. If your modem's ip is 192.168.0.1 then it must be written as 192.168.0.2.


nat-start script:

#!/bin/sh
iptables -t nat -I POSTROUTING -o `nvram get wan0_ifname` -j MASQUERADE


(This rule uses the NAT packet matching table (-t nat) and specifies the built-in POSTROUTING chain for NAT on the router's external networking device. POSTROUTING allows packets to be altered as they are leaving the firewall's external device. The -j MASQUERADE target is specified to mask the private IP address of a node with the external IP address of the firewall/gateway.)

(Don't forget to chmod +x /jffs/scripts/*start)

Before adding scripts, you can check if this works for you easily. Just SSH to your router and enter the commands in the scripts (you can use copy-paste). Then open a browser session to your modem (192.168.100.1 in my case) and there is your modem interface.

Adding scripts just makes sure that the commands are run on router startup.