Linux – SSH Remote Port Forwarding (Tunneling) not working publicly even with GatewayPorts yes

"Connection reset by peer" means the TCP stream was abnormally closed from the other end. I think the most likely explanations are that the remote server process handling the connection has crashed, or else some network device (like a stateful firewall or load balancer) has decided to interfere with the connection.

You need to debug this on the remote server if you can. sshd logs through syslog, and on a typical Unix system the log entries will be in one of the files in the /var/log directory. If you're lucky, sshd will be logging something every time it drops your session.

If you have root access on the server, you can run a debugging instance of sshd. Become root and then run:

/path/to/sshd -ddd -p 1022

This will run an instance of the SSH server which will listen on port 1022, accept one connection, and print debugging information to your terminal. Run your client as usual, except specify port 1022 as the port:

ssh -p 1022 user@host

The debugging information printed by the server will hopefully make it clear what is happening.

Edit: The server output indicates that the server isn't crashing or deliberately closing the TCP connection. Something else is causing it to close. I would take a look at any security software installed on the server which might monitor TCP sessions, as well as any firewalls, load balancers, or similar network hardware which might be part of the local network.

This technique works, but is not very good for accessing websites since you need to forward a port for each and every domain being accessed. If you load slashdot in chrome and use the developer tools, you can see that when you load slashdot it is actually loading content from at least 21 different domains. If you are only forwarding one domain then you won't see all the content.

Another problem is that you are tunneling to port 80 on a site that is serving content on port 443. If you run "curl -i slashdot.org" you will see that it serves you a 301 redirect to HTTPS. When the browser tries to follow the redirect to HTTPS everything will fail.

You would be better off using ssh as a SOCKS proxy and configuring your browser to use it. You can open a socks proxy on a local port like this:

ssh -D 8080 myhost.com

myhost.com could be "localhost" in your case, but usually is a remote server. Once you have this session open, just go into browser preferences and configure the browser to use a SOCKS v5 proxy pointed at localhost port 8080 (easier to do in firefox than chrome imho). Once that's done the browser will run all of its traffic through the ssh tunnel.

This can be incredibly useful for accessing websites hosted on private networks, or encrypting your data across a network you think is not secure.