You can use ssh with reverse tunnel like this
ssh -fNR 2222:localhost:22 username@domain.com
-f: run in background
-N: execute no command
-R: reverse tunnel
2222:localhost:22: mapping remote_host:2222 to localhost:22
remote server
connect to remote server via ssh and then type
ssh local_machine_username@127.0.0.1 -p 2222
Done! It's great!
autossh
If you want to keep the tunnel always alive, one way is to use autossh. It will automatically spawn a ssh command once the link is broken.
install
sudo apt-get install autossh
We're going to run autossh in background. However, unlike ssh, in autossh, -f won't let you type password, so you have to use public/private key to authorize.
key
ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa): ~/.ssh/some_key
(enter to the end)
config
Config ssh server for shorter command, in ~/.ssh/config
Host reverse-tunnel
HostName domain.com
User username
ServerAliveInterval 30
ServerAliveCountMax 3
IdentityFile ~/.ssh/some_key
Use
First, copy key to remote server (do only once)
ssh-copy-id reverse-tunnel
start ssh reverse tunnel with autossh:
autossh -M 0 -fNR 2222:localhost:22 reverse-tunnel
-M: monitoring port, use 0 to disable. It is said by official doc that the better way was to set ServerAliveInterval and ServerAliveCountMax to do this job rather than open an echo port to monitor.
Stop ssh tunnel
You need to first stop autossh command itself and ssh process it has spawned.
stop autossh
pkill -9 autossh;
stop ssh
ps aux | grep reverse-tunnel
kill {pid}
Or in short, add it in .bashrc
alias killautossh='pkill -9 autossh; ps aux | grep reverse-tunnel'
