Wall of confusion

September 21, 2008 6:53 AM

Safely use someone elses ADSL connection ?

I'm a long way from home and I need to hook my PC up to my hosts ADSL connection.

They have an ADSL modem (D-LINK DSL-302G) but no other hardware protection (and with NAT disabled on the modem currently).

I have a Windows XP SP2 machine using Windows firewall (I also have in my bag a WRT54G Linksys router).

I don't want to mess with my hosts setup and I don't have a manual for the WRT54G (I've tried various things with the 54G and failed to connect)

What's the safest way for me to make use of their modem ? My current ideas range from :

* plug in directly to ADSL - hope Windows firewall can handle it
* go and buy replacement ADSL modem but with built in firewall (not easy long way from shops)
* install some extra layer of software firewall

All suggestions welcome

posted by southof40 to computers & internet (6 comments total)

What are you afraid of happening?

Plug & Play.

I'd go right into the wall if he has that set up, take a line off his modem if it's a switch as well, or plug your Linksys into the modem and take a line off there.

I think maybe I am missing something or you're making it too difficult.
posted by cjorgensen at 7:06 AM on September 21, 2008

I'm very confused. Why can't you just plug your computer right into his router? You have to be sane while out on the Internet, but if you've got Windows Firewall set up to block most ports and only allow through the ones you actually want, it'll be fine. Firewalls don't really have strength like they're medicine or physical barriers.
posted by Tomorrowful at 7:17 AM on September 21, 2008

Agree with the above. As long as you are safe and you keep your computer patched you should be ok.
posted by mmascolino at 7:58 AM on September 21, 2008

The Windows Firewall is fine. Turn on, plug in.
posted by Mwongozi at 8:29 AM on September 21, 2008

For a normal ADSL modem, the setup you want is ADSL line -> modem -> router -> computers. Ie: unplug their computer directly from the modem and plug it into your WRT54G. If that works then plug your own computer into the router too. Voila!

The trick is you have to configure the router. The simplest way is to emulate the settings of whatever PC they have plugged into the modem, including cloning the MAC address to the WAN port. You can download a WRT54G manual online easily enough to help you with the configuration.

I'm not familiar with the DSL-302G, but looking at the online spec sheet it says "supports 2 computers simultaneously" via the USB and ethernet ports. That may be a simpler way to get things going. You say they've "disabled NAT", which suggests maybe that 2 computer thing isn't going to work without reconfiguration, but I dunno.

Windows connection sharing / firewall is a whole different way to get it working. I have no experience with it, so can't help.
posted by Nelson at 8:35 AM on September 21, 2008

Just plug into it. Windows firewall is fine. The only real remote exploit is the RPC exploit and that was patched in 2003. Don't worry so much.
posted by damn dirty ape at 9:06 AM on September 21, 2008