[linuxguru]

How can someone email me through my server while i have private ips
is there a way i can dail into another linix computer and have that as a gateway to my server?

Thanks for reading my post.

[edifice]

Ah, using linux as a gateway, eh!! Let the fun times begin.

You have two solutions. Do the easy thing (like I did) and buy a router with DHCP support. If you have a few windows computers running on the network as well as linux ones, this will save you some time. The router will automatically set up the ip addresses and let you enable port forwarding, which is what is needed in order for private internal ips to communicate with the outside world. The cost of my router, a linksys one, was around 72 bucks and was a quick solution to my needs.

The other solution is looking into port forwarding. Depending on what distro you decide to setup the gateway/router with, it can be difficult or hard. I would suggest using one you are comfortable with before doing so. Basically, what port forwarding does is translate your internal ips to the outside world. So, if you want to receive email on your server from a friend and you are behind a gateway, it would look something like this.

Your friend sends an email with his public ip, say 24.53.98.12 via port (just random) 4890.
The email hits your gateway. It sees it is coming from an public ip and from port 4890. Port 4890 is the established port you guys decide on using. Now, you set up port forwarding on your gateway to send any information on port 4890 to let's say the computer on your lan with the address 10.0.0.100. Since this is email, you probably want to use smtp (simple mail transfer protocol) and have any email come in on port 25 (default port for smtp). So this is what happens at the gateway. The email is delivered to your public ip via port 4890. It hits your gateway, and the gateway starts port forwarding. It takes the email with the public ip and forwards it to your box. It would look like this:

friend (24.12.45.65:4890)---> email(destination is you at say 24.90.43.87:4890) --> your gateway takes the email with its destination and look at the port, and forwards it to the right computer behind it so (24.90.43.87:4890 is forwarded to 10.0.0.100:25) which is your server. To go back out, it sends it the exact opposite way.

If by now you aren't confused, congrats! However, there are several sites that will be very helpful. I have included one below.

http://www.ox.compsoc.org.uk/~steve/portforwarding.html

To find more use google search for: port forwarding and email or port forwarding and linux, or simply just port forwarding for a better explanation on how to accomplish your goal. Good luck.