Hi everyone,

I am having a really hard time setting up an SSH tunnel. I have looked at tutorials and how-to pages everywhere, and I find the man pages confusing. I am wondering if someone can provide me with the command to do what I am trying to do. I will be as detailed as possible.

I have a server running behind a NAT device that I can SSH to on an unconventional port (1106). The reason for this is we have a lot of development servers behind the same NAT and we have to have different SSH port forwarding for each one. I want to run gdbserver on this machine and connect to it from my client workstation. I want gdbserver to run on port 9160 on this machine behind the NAT. Since I don't have access to the NAT router, I can't set up port forwarding to access this port on the server, so I need an SSH tunnel. I want to be able to point my gdb client to port 9161 on my local workstation, and I want this to be forwarded over SSH to port 9160 on the server, using port 1106 for SSH. Here is the command I have been trying:

ssh -L 9161:localhost:9160 admin (at) my-server (dot) mydomain (dot) com -p 1106 -N
It seems like this should work. But I keep getting the error:

bind: Cannot assign requested address

And if I try to connect to port 9161 on localhost, I get an error:

channel 1: open failed: administratively prohibited: open failed

and the connection is closed immediately. I definitely am listening to port 9160 on the server, but it is acting as if we are getting a connection refused or something. When I look at wireshark, I don't see any kind of attempt to connect to the server whatsoever. So most likely there is something wrong with my command.

Any advice?
Thanks in advance.

That looks like it should work, maybe the server you're connecting to doesn't allow unprivileged users to set up forwarding?

Could you set up a reverse tunnel initiated from my-server.mydomain.com to your local machine?

The only thing that might be incorrect might be the order:

used@hostname comes last always, unless there is a remote command also.

Welcome to LinuxQuestions.

If the tunnel is connecting to the remote ssh server itself then using localhost is valid. The problem could be a IPV4/6 issue. You can also try: