What's a firewall?

[PIBby]

Anyone know?

[JazzyManda]

a firewall is a software or something that keeps people from hacking into your computer. it also keeps down pop up adds.


Amanda

[OlivierDetraz]

Here is what I found about what a firewall is on Google: http://www.tidbits.com/tb-issues/TidBITS-468.html#lnk3.

[Will]

A firewall is a piece of hardware or software that restricts access to a computer from the outside. Most hardware firewalls also allow many computers to share one IP address.

A firewall on a home computer is most useful for blocking trojans and spyware from working. These pieces of software can still get on your machine, but nobody can use them to control your computer or spy on you. That is, if your firewall is configured correctly.

I could give a more technical, complete, and correct answer... but this is all most home users need to know.

[Zebrakorn]

Reminds me.. I need to sort out a proper firewall rather than using the crappy Windows XP one.

Actually.. you might be able to give me some advice, m125, or Pete, if you're reading this..

At work I'm sorting them out with an adsl installation, so there's going to be a fixed IP going to an adsl router on a network with three systems. The router has DHCP, although I have a feeling I might end up not using it. One of the systems has IIS running so it can host the intranet and I've got port forwarding set up on the router so that port 8080 points to that pc.

Question is .. do I need any firewall software running on the PCs or is the router likely to to cut out any threat? I've been thinking that if it has port forwarding set up, then people will be able to get to the computer running IIS, so maybe I should just have firewall software running on that system?

The reason I'm going to have the port forwarding set up is so that I can have the intranet accessable externally.

[Will]

So, you are using NAT? As long as 3389 or something isn't being forwarded, you should be somewhat safe. As long as the interal addresses aren't routable, they can't touch your systems unless they get around the firewall somehow.

I personally wouldn't use DHCP with such a small network. Manually set an internal 10.x.x.x, 172.31.x.x, or 192.168.x.x address for each one. You never want a server to use DHCP. Even though you can set the lease not to expire, I have run into cases where Windows does after being told not to. ("10.1.0.49 is supposed to be server-labs2. Now your telling me that a rlookup yields hhslrm51-12?!")

[Zebrakorn]

Yeah I've got them set up as 192.168.0.1 to 3 and then .10 for the printer. I want them on a fixed IP so I can have more control .. there's only three of them .. and one of them needs to be a webserver anyway.

Thanks for the advise. I had a feeling it would be moderatley safe. The only port that's going to be routable will be 8080, which has to be.