I have a domain that i bought from DynDNS. I pointed the domain at my ip adress so i can run servers. The problem I have is that I don't live near the server computer... Can I use an ssh tunnel? As I understand it, this will let me have access to my servers. I want the remote computer to direct traffic from port 8080 over the ssh tunnel to the ssh client, being my laptop's port 80. Is this possible?
This is actually pretty easy to accomplish, even though it's somewhat buried in the ssh documentation. Assuming OpenSSH, the basic syntax is as follows:
ssh -R 8080:localhost:80 -N firstname.lastname@example.org
This will open a listening socket on port 8080 of your-server.dyndns.org, and any connections that are made onto
your-server.dyndns.org:8080 will be forwarded over the SSH tunnel to the computer which has opened that SSH connection, and from there will be directed to
-N option instructs SSH not to open a shell or whatever, just to establish the port forwarding, so you can send it into the background and leave it running.
Putty uses pretty much the same syntax, but wrapped into some sort of GUI. The principle is the same though.
But be careful in what you do. Since you're essentially funneling external traffic into your network, you are pushing a hole in your network's firewall. If it is not your network, your admin may object to this and take you responsible—usually there is a reason why you are not allowed certain kinds of traffic.
To by able to forwarded your local port 80 not only to the loopback interface (127.0.0.1) you have to configure
GatewayPorts clientspecified in
/etc/ssh/sshd_config on the remote machine first.
Then forward your port with:
ssh -R 0.0.0.0:8080:localhost:80 -N email@example.com