Firewall and DSL questions

[Dave Anderson]

Okay, first a little background information. Last week my dream finally became a reality - DSL is available where I live. I ordered it immediately, of course. Today the equipment arrived and confirmation that the line was ready. It's one of these self-install kits.

Now, this is Verizon DSL. I know it can work with Linux and nearly any other OS that's out there. Here comes my questions:

I have a home network already. 2 XP desktops and an XP laptop, all attached to a Slackware server running Samba. The Slackware server stores all the crucial data files - school work, documents, etc.

I want to build a firewall. After reading up on firewalls, it seems their primary purposes is to isolate the rest of the network from the outside world. All Internet traffic comes in and out of that firewall, since it would be the DSL connection (gateway) to the outside world.

Now, I assume the firewall should NOT be on my Samba server, since it stores critical data files. What I'm getting at is, won't outsiders still be able to try and hack into the firewall? And if that's the case, I assume critical files should not be kept on the firewall and that all it should be doing is acting as a firewall/gateway.

Is that right?

Finally, a co-worker told me I should be able to plug the DSL modem directly into my hub, since the DSL modem should have its own unique IP address. Can anyone confirm that for me?

For now I just want to hook the DSL modem up to my XP box and get on the Internet, so I can experience some high speed action. I have a machine I'll be upgrading soon, at which point I'll build a firewall. Thing is, my XP box only has one network card, and that's in use on the network. If I add the DSL to that machine, do I add another network card to it (I know this is one possibility), but could I simply plug it into the hub?

Thanks!

[Choozo]

Check out SmoothWall (http://www.smoothwall.org) if you have a spare PC lying around. Excellent firewall/router with its own DHCP server and VPN capabilities.

The 'donor PC' don't have to be anything hotter than a 486 or low-end Pentium with about 16 MB of RAM, and a harddrive at approx. 100 MB up to 500 MB will do fine.

Cheers :)

[X_console]

A good firewall is one that isn't on the machine you're using. As it was already said, a 486 is good enough. Run Slack or OpenBSD on it and you're good to go. This 486 should be as secure as possible. That means no bleeding edge software, no unecessary services or programs running. A barebones system. You can even download floppyfw and run a 486 firewall using a Linux floppy: http://www.zelow.no/floppyfw/ Running off a floppy might be a good idea because 1: in the event of a power failure, the filesystem won't be damaged because there is none. 2: If someone does break in, rm -rf / won't do any damage. Just pop the floppy back in, reboot, and you're back. The downside of course is that you can't do as much as you would like on a floppy because there just isn't enough space.

[Eroberer]

Cool. Could you do the same thing on a CD-RW but with more options due to more space?

[mangeli]

Check the NHF on here about the firewall/easy internet sharing. And no, you cannot just plug the dsl modem in to the hub. You have to have a dsl router (which lynksys makes and bestbuys sells) to vend it out to the networked computers. Its up to you whether you want to spend the $150 on the router or build your own.

I've done both (I bought a wireless router for my boss and I built my own router/firewall/webserver for myself)

[X_console]

Originally posted by Eroberer:
<STRONG>Cool. Could you do the same thing on a CD-RW but with more options due to more space?</STRONG>

You need to have a bootable CDROM drive and it should work.