I'm trying to generate an SSH server in a machine behind a router.
First I tried to bind the SSH to my public IP address:
Then I'm prompted with a password request, however my username password doesn't seem to work.
Obviously I know my username password, so it seems to me that it's trying to authenticate in another computer under the same network.
Any suggestions how to fix this?
It would also help me any alternative on how to create an SSH server behind a Router when you don't have access to the Router.
The ports in iptables are all open.
UPDATE
As suggested by Thomas Oster answer I've tried the following.
In the machine behind the router I've executed the following command:
$ ssh -R10002:localhost:22 <remote_public_ip_address> -l <my_remote_server_username>
<remote_ip_address> being the remote_ip_address of a server with public IP and SSH server on which I have full control.
<my_remote_server_username> being the remote server username.
After that, I've tried to connect from the remote server to the server behind the router like this:
$ ssh -p 10002 <remote_public_ip_address>
However this command displays the following output:
So I opened the 10002 port in the iptables firewall using the following command:
After that I've executed again the command but it displays the same error message.
In my machine behind the router I have all ports open in iptables.
UPDATE 2
You have to allow port-forwarding in the /etc/ssh/sshd_config of the
remove_public_ip_address server
I've tried to allow portforwarding in the sshd_config file adding this command:
But it gave me this error message:
After "ssh -R...." did you leave the window open?
After executing that command, it connects to the remote public machine, and yes, I left the window open.
Can you use ssh -p 10002 localhost on the public server after the
tunnel is created?
Yes, if I execute that command in the public server, it connects after asking me for credentials.
Please try "ssh localhost" on the machine behind the router to check if sshd is running and working.
This also works.
UPDATE 3
I've been finally able to make it work (thanks again to Thomas Oster)
We are going to work with three machines:
Destination Machine: That we want to connect to.
Middle Machine: A server acting as an intermediary for the connection (a Linode in my case)
Home Computer: Where we will access to the destination machine.
These are the steps I followed
Step 1:
Add the GatewayPorts option:
GatewayPorts yes
Restart ssh.
Step 2:
This will link your public machine with your destination computer via port 4040
It will connect to the middle machine and prompt the terminal, you must leave this tab open.
Step 3:
Connect from home:
Or connect from the middle machine:
Source