Tuesday 15 December 2015

Access your modems web admin screen from behind a T-Link Archer C2600 router


These instructions will no doubt work for other Tp-Link routers out there.


Assume you have a Cable/DSL modem on 192.168.0.1/255.255.255.0 and the T-Link is on the
default 192.168.1.1/255.255.255.0

If your modem / router are both on the same ip network, i.e. they both use 192.168.1.1, then you'll need to reconfigure one of them to use a different network.

Plug your modem directly into you computer, or LAN switch.  You should be able to access it at http://192.168.0.1.  Now plug it into the WAN port on your router, you can no longer access it.

PC<192.168.1.2> -> Router LAN interfance<192.168.1.1> -> pppoe to the modem -> internet.

The problem is your PC can't access the modem on the local network, as the modem is on the WAN port of the router which is a separate physical network.  So it tries to route the request to the default gateway (the router).  The router only knows about your 192.168.1.1 network, so it routes to its default gateway over the PPPoE WAN interface onwards to the ISP who also knows nothing about your modem being on 192.168.0.1

  1. Login to the C2600s router admin page.
  2. Goto Advanced => Network => Internet => Advanced
  3. Specify a secondary connection.
    1. Connection Type: Static IP
    2. Ip Address: 192.168.0.3
    3. Subnet Mask: 255.255.255.0
  4. Leave all the other advanced settings alone.
Check the "Advanced Routing" page. you should see a new entry for 192.168.0.0 on the wan interface.

IDNetwork DestinationSubnet MaskGatewayInterface
10.0.0.00.0.0.0xxx.xxx.xxx.xxxinternet
2xxx.xxx.xxx.xxx255.255.255.2550.0.0.0internet
3192.168.0.0255.255.255.00.0.0.0wan
4192.168.1.0255.255.255.00.0.0.0lan

Now when your PC routes the request for 192.168.0.1 to the router, the router knows it can access that address via the WAN interface, instead of forwarding it to the default "internet" interface.


http://192.168.0.1 should bring up your modems admin page so you can check DSL stats etc.

This was tested on Firmware 1.1.2/20150924/66045

Enjoy. 




7 comments:

  1. is there a similar way for Netgear routers?

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    Replies
    1. No doubt there is, but i'm not familiar with the web admin console for netgear routers. You want to assign an ip to the WAN interface and then setup a route basically. Pretty sure most routers i've used allow to setup routes manually, but adding the ip to the WAn interface, maybe not. It was hiding in a rather unexpected configuration section on the TP-Link

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    2. Another alternative, is to connect the modem to one of the LAN ports, so it's on the internal network and you can access it, then connect the WAN port to one of the other LAN ports, so the router can still access the modem where it expects to find it.

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    3. I do similar thing as on your second advice but with switch and if it is connected permanently when new device is connected to network it gets external ip from ISP trough LAN and existing internet connection disconnects. it might be becose Talktalk FTTC dose not require authentication.
      Maybe i could get it working with managed switch?!

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  2. Awesome, works a treat with my Draytek Vigor 130 and TP-Link Archer C3200 setup. So happy I can view my modem stats without disconnecting the WAN connection from the 130 to the C3200. Cheers for this guide!

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    Replies
    1. I have the same setup. This works perfect. :)

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  3. Great article. I'm trying to get this working with a Draytek 2860Vac as my router (192.168.16.0/22) and a Vigor 130 as the VDSL modem still set to factory (192.168.2.1/24). No joy as yet :(

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