[sclug] SSH / Cable modems

[Bob Franklin]

On Mon, 5 Sep 2005, Peter Brewer wrote:

> My dad has got a BT cable modem connected to his Ubuntu machine via an 
> ethernet cable.  I want to be able to SSH into it to help out with 
> problems. Does anyone know if it is possible to port forward from the 
> modem without a router?

Cable modems are just bridges (IME); they can connect to your PC with a 
USB connection or Ethernet.  Either way, the IP address sits on the PC (or 
whatever) you've connected; not on the modem.  At home, I have a Linux box 
doing the NATing and routing between the internal network and the cable 
network/Internet.

So, if the connected box is a Linux box, you can SSH straight in.  If you 
have more than one machine, you'll need to get a router or use the 
connected box as one.

[Of course, I would make some suggestions about security - perhaps move 
SSH to a non-default port and limit connections to key-based 
authentication, certain accounts, etc.]

   - Bob


-- 
  Bob Franklin <r.c.franklin at reading.ac.uk>          +44 (0)118 378 7147
  Systems and Communications, IT Services, The University of Reading, UK