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Thread ID: 56009 2005-03-25 00:32:00 Using Linux PC as a type of firewall? Midavalo (7253) Press F1
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337794 2005-03-25 00:32:00 I have a spare PC which has Linux on it. How would I go about using that as a type of firewall for my adsl connection? How I figure it would work would require 2x network cards in that machine - one to connect to the modem, and the other to connect to the second (main) PC? Otherwise just connecting both PCs to the modem (4 port) would kind of defeat the purpose wouldn't it?

Midavalo.
Midavalo (7253)
337795 2005-03-25 01:00:00 www.smoothwall.org/

Have a look at this
Dannz (1668)
337796 2005-03-25 01:05:00 www.smoothwall.org/ (http://www.smoothwall.org/)

Have a look at thisI don't think the OS is the problem here - I need to get the hardware set up correctly first for it to work properly... or will Smoothwall help out in this area?

M.
Midavalo (7253)
337797 2005-03-25 01:10:00 SmoothWall will use more that one network card and the firewall can be connected to a hub or switch Dannz (1668)
337798 2005-03-25 01:13:00 What distro do you have installed at the moment on it? Some are more suited for this purpose than others. Smoothwall is a specialised distro for acting as a firewall/security only.

You will need two NIC's in the machine - one for the ADSL connection and the other for the LAN boxes. The Linux firewall will be the man in the middle box between the www and your lan.

I've never set up a system like this before, as I rely on my ADSL modem/router's NAT to provide a layer of security.
Jen (38)
337799 2005-03-25 01:19:00 Distro Watch Firewalls & Routers (distrowatch.com)

Do's & Don'ts (searchenterpriselinux.techtarget.com) of configuring Linux routers.

Roll Your Own Firewall (www.linuxjournal.com)

I haven't checked the whole lot and most would be beyond my current ability, but you might find it helpful.
Murray P (44)
337800 2005-03-25 10:46:00 You will need two NIC's in the machine - one for the ADSL connection and the other for the LAN boxes. The Linux firewall will be the man in the middle box between the www and your lan.I don't want to use 2 NICs in the machine (because the machine is too small for another one).

Just been talking to someone who has this kind of setup at his work and he said that they have the ADSL router plugged into one of the switches, as well as several PCs, but the PCs are set to connect through a LAN to a proxy server (the linux box) and then get the internet via that, so obviously it can be done - the next step is to figure out how :D

Feel free to offer any more suggestions ;)

Thanks for all help given so far though - now suggestions for required OS will be more appreciated :p unless the standard Linux whatever distro that I might have installed (Mandrake, Fedora, whatever else I might happen to install) will do the job for me.

M.
Midavalo (7253)
337801 2005-03-25 11:05:00 .... but the PCs are set to connect through a LAN to a proxy server (the linux box) and then get the internet via that, so obviously it can be done - the next step is to figure out how :D



Yes but I think you will find that the connection from the LAN to the proxy is via the one NIC and to the internet via the other NIC.

All Linux distributions have iptables included to build a firewall. But some are designed as firewalls only. There are lots of scripts you can download or you can use a GUI one like Firestarter.
johnd (85)
337802 2005-03-25 11:09:00 Some sample scripts:

www.ecst.csuchico.edu

Firestarter:

http://www.fs-security.com/
johnd (85)
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