Using a linux as a router

[Jassi]

Here is the situation in a nutshell:

There are over 100 people that connect to a wireless in my apartment complex (student owned and run, so we don't have a dedicated network admin). The PC running SuSE 9.3 and setup as a router is a Celeron 375 MHz. The problem is that something happened in the last month and the setup doesn't work anymore. The server feeds into a switch and a wired backbone that connects about 9-10 wireless G (Linksys WRT54s) routers to supply internet to the building.

As you can imagine, the traffic is probably huge but it has been working for over a year. The person who set it up moved out and I am trying to bring it back to its formal glory.

Here is what I've tried so far:

I used PuTTy to SSH in to the server and I can successfully ping 4.2.2.1 which I believe is a major DNS server. BUT I can't use the browser to access the net. I am about to try to ping some more servers (Google, M$..) and see if I can access the net outside of the LAN.

What I could use help with:

I need to know how I can setup or find a preconfigured a script or something that will allow me to enable a net connection. I am also open to changing the OS to a more suitable flavor of Linux. As a secondary goal, I'd like to set up a file server on the server as well for people within the LAN.

Thanks for all your help, I hope my babbling was coherent (I'm new to Linux and Networking).
Jassi

 

[n0cmonkey]

If the system is a firewall, don't set it up as a file server. Get a second box.

What isn't working exactly?

You can ssh into the system from your machine, so the box is alive.

You can't access the net from a browser on your machine? On someone else's machine? On the router?

If you traceroute from your machine to 4.2.2.1, where does the traceroute stop?

What is the output of cat /proc/sys/net/ipv4/ip_forward on the firewall machine?

EDIT: Not everyone has the root password to this box, do they?

 

[nweaver]

tbh...I would tell you to ditch Suse (unless you know/understand the administration and iptables) and use smoothwall or something geared toward that. I have 60 subs on a smoothwall P3 550 that works great.

 

[Jassi]

Originally posted by: n0cmonkey
If the system is a firewall, don't set it up as a file server. Get a second box.

Done. I won't mess with it, its a low priority compared to getting the net access working again.

Originally posted by: n0cmonkey

What isn't working exactly?

You can ssh into the system from your machine, so the box is alive.

You can't access the net from a browser on your machine? On someone else's machine? On the router?

I can ssh fine. I can ping google, msn and bunch of other sites. I have a laptop connected to the server via a wired switch and I can't ping or access the net from my laptop. Which is really odd because unless the box is specifically configured to block all packets, I should be able to ping the box, the modem and the outside world. Since I am complete n00b when it comes to Linux networking, I have no idea where to start to get the access back up.

I need to do a trace route and post the results, I'll look up how to do it.

 

[Jassi]

How difficult is it to setup Ipcop or Smoothwall just for the purpose of sharing the internet and setting up a firewall?

 

[kt]

You can get Smoothwall up and running in about 30 minutes.

 

[n0cmonkey]

Originally posted by: Jassi
I can ssh fine. I can ping google, msn and bunch of other sites.

From where? The firewall, a wired machine, or a wireless client?

 

[Jassi]

Thanks for the help guys. I met someone who had much more experience with linux and networking and he setup a FC5 box to act as the router. The net is up and running and hopefully much more stable than before.