new file server questions

What I'm trying to do is create a new system that will act as a personal file server that will be always on.

The question of security popped into my head almost instantly.

It will be on a shared internet connection and will be behing a router.

What I'm looking for is suggestions on a firewall. What particular firewall would be best for this kind of application?

Also, if there was a firewall on my system, I was on say a friend's computer or a public terminal, and I needed access to my server, would I be able to get access to it and how?

Thanks!

Well if the router has NAT, I dont think ? You'll have to worry about anything.

DDR-PIII is right, the Router should protect it (unless you get a virus, or enable DMZ).

What kind of file server do you plan to run? If it's SMB (Windows file sharing) server, then you will only be able to connect to it on your LAN. (You can open it up to the internet, but that is a security hazard). If it's FTP, then you need to map ports 20, 21 on the router to your fileserver.

If you are worried about it, put a software firewall on it, like zonealarm. That should keep the nasties away.

if your just hosting lan files, and you have a linksys router, make all your lan ips static and then in the linksys router config page, assign the ip of the server as a private ip, meaning, no data will be sent to/from the server onto the wan, and it will just be on the lan

What if I'm trying to access it outside of the LAN, IE at work, the school lab or something not hardwired to the router. Can I still get access to it via the Internet?

Also, if I need a software firewall, can someone suggest one for me?

What sort of file sharing are you running on it? If your doing Windows file sharing, openning it up to the Internet would be a major security problem.

FTP is another option, but even that is not very secure. You would access the FTP server via a client. You would need to point the client to the server's external IP address. And like su root said, you'll need to forward ports 20 and 21 on the router to the server (assming you are not using passive mode, in which case you'd have to forward a range of ports).

Zonealarm seems to be a good software firewall, although a router is probably sufficient security.

I was trying to set up an FTP, so I can go and connect to it from wherever I happen to be. But if I install a firewall, that prevents me from accessing it from anywhere, doesn't it.

You can tell the firewall to allow ports 20 and 21 to be open for ftp traffic. This will allow your FTP server to function.

Note that if your using passive mode on the server, a different range of ports will need to be opened. Generally, port 21 and a range of unprivledged (1024+) ports. Check your FTP server's documentation or options to see what mode your running in.