I'll try to make this as short and complete as possible. I recently switched to Linux and am trying to get a server setup to do interal file sharing, external mail, ftp, web, and vpn.

I am an @home user and had all the above setup on win 2k box so I know that it will work. I am using tzo for my dynamic dns and using my isp dns servers for all my dns. This is how the setup worked before.

Current configuration is as follows (using SUSE 8.2 Pro for all Linux machines):

@home cable -> Linksys Router -> internal network that consists of my Linux box (server) and 2 Win XP machine along with Linux on a laptop. I have given my Linux Server a static ip of 192.168.1.100 and manually entered the DNS from my ISP. I have set the hostname and the domain on the box. I have gone into my router and placed the Linux Box in the DMZ as well.

So far file sharing in the interal network works fine. No problems there.

Using Postfix (and reading through as much as I can on the net) I have it setup and can send email out, but get no email back in?!?!

I have not configured any type of fire wall but on a port scan at grc.com all my ports are closed. Is this the problem? If so where is the config file for iptables to open them up? I tried enabeling the SUSE firewall but after another scan they still show closed? On my 2K box they would show open so I am hoping that I am going in the right direction here on why I can't get any email from the outside world.

Outlaw

From what I see.. you want to be able to access that computer form the outside
Go into your router, and make a DMZ, it's under the advanced tab (or something like that)
Enter your computer's internal IP there.

What this does is.. it routes all external connections to that comp, instead of the router, or of the comp it is configured for now. That'll let you receive email from the outside. Though be warned.. people will be able to portscan you.. and your computer will not be procteded by the router. Much less secure. I'd run some kind of firewall on that computer. (on all, but especially that one) Check out tldp.org for a tutorial on securing linux.

Happy emailing

Rather than setting up a DMZ, I'd just investigate port forwarding with your router. Linksys routers can forward any port to any IP (that is what I do so I can access my linux box via ssh). That way you're just forwarding the ports you need. No sense in exposing your entire machine when you only need to feed a few services.

It is already in the DMZ, and I have tried using the port forwarding. The problem is when I scan the Linux box it is showing the port as closed on grc.com. Should it say closed or open? On my Win2k box those ports (SMTP, WEB, FTP) would show open. Please note that I am running SUSE 8.2 and have the firewall turned off.

If I enable to firewall under SUSE and select these services (SMTP, WEB, FTP) to run they still show closed. I can even take my router out and plug straight into the cable modem. That is why I want to know if I need to modify IPTABLES to open the ports.

Outlaw

The only way to know if your firewall is causing the trouble is to either turn it off and try connecting to your linux box or post it and let us take a look.

Try posting the output of iptables -L