Connecting an ADSL router to an Ethernet WAN FREE cabling and networking Helpdesk
 Question by Darren Wetherilt posted 30 Apr 2004
 Connecting an ADSL router to an Ethernet WAN
I have an ADSL router with an RJ11 socket which connects to a phone line. My broadband connetion is Ethernet based (ie the socket on my cable modem which connects to my LAN is RJ45). I would like to use the router primarily as a firewall which will sit between the cable modem and the LAN. I'm sure this must be possible with the aid of a RJ45 to RJ11 cable but I'm not entirely sure what the pinouts should be. I have read another post on here which suggests to use the RJ11 plug in the RJ45 socket, but I'm sceptical as to whether this will actually work. Can somebody give me some definitive advice? I have crimping tools etc to make a cable but like I said, I need to be sure what the pin-outs should be.
 Answer by Dmitri Abaimov posted 30 Apr 2004
Dear Darren,

I have a feeling that you are confusing an ADSL modem for a router. A router (a residential gateway in this case) should have an RJ45 port on one end that is marked "WAN" and at least one other RJ45 port on the other end that's marked "LAN". Sometimes the LAN ports are not marked, and sometimes there are multiples of them (4 or 8). Some models have DB9 port on them for external modem hook-up to use it as a backup for broadband service.

From your description it looks like your device is an ADSL modem, essentially a DSL counterpart of your cable modem.

it will be easier to help you if you let us know what is the model number of the device, and who is the manufacturer.
Dmitri Abaimov, RCDD

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