# Forward ports with a reverse SSH tunnel
- no port forwarding needed on the LAN of the host
- encrypted connection
- hides the IP of the host
- a Virtual Private Server (VPS) - eg. a minimal package on Lunanode for ~3.5$/month
- root access on the VPS - only root can forward ports under no. 1000
- ssh access to the host computer (where the ports will be forwarded from)
# On the host (your BTCPay Server instance)
# switch to root user (if not logged in as root) sudo su - # check for an existing ssh public key cat ~/.ssh/*.pub
If there is none generate one (keep pressing ENTER):
ssh-keygen -t rsa -b 4096
This will generate the SSH keypair
id_rsa (private key) and
The private key needs to get added to the ssh-agent:
# start the ssh-agent in the background eval $(ssh-agent -s) # add private key to ssh-agent ssh-add ~/.ssh/id_rsa
Copy the public key over to the VPS (fill in the
You will be prompted for the root password of the VPS.
ssh-copy-id -i ~/.ssh/id_rsa.pub root@VPS_IP_ADDRESS
To verify that it works, SSH into the VPS – this should not prompt for the password anymore:
# On the VPS
You can either reuse the connection from before or login as root.
Edit the sshd config:
sudo nano /etc/ssh/sshd_config
Make sure these entries are active (meaning there is no
# at the beggining of the line).
Alternatively, you can just paste these on the end of the file:
RSAAuthentication yes # not needed on latest OpenSSH versions PubkeyAuthentication yes GatewayPorts yes AllowTcpForwarding yes ClientAliveInterval 60
CTRL+O, ENTER to save, CTRL+X to exit.
You can lose access at this point if the sshd config is wrong. Please double-check!
Restart the sshd service:
sudo systemctl restart sshd
# Back to the host (your BTCPay Server instance)
# Install and set up autossh
sudo apt-get install autossh
Create the service file:
sudo nano /etc/systemd/system/autossh-tunnel.service
Paste the following and fill in the
Add or remove ports as required.
[Unit] Description=AutoSSH tunnel service After=network.target [Service] User=root Group=root Environment="AUTOSSH_GATETIME=0" ExecStart=/usr/bin/autossh -C -M 0 -v -N -o "ServerAliveInterval=60" -R 9735:localhost:9735 -R 443:localhost:443 -R 80:localhost:80 root@VPS_IP_ADDRESS StandardOutput=journal [Install] WantedBy=multi-user.target
Enable and start the service:
sudo systemctl enable autossh-tunnel sudo systemctl start autossh-tunnel
The port forwarding with a reverse ssh-tunnel is now complete. You should be able access the ports/services of the host computer through the IP of the VPS.
Check if there are any errors on the host computer:
sudo journalctl -f -n 20 -u autossh-tunnel
To check if tunnel is active on the VPS:
- Raspiblitz FAQ: How to setup port-forwarding with a SSH tunnel? (opens new window)
- RaspiBolt Docs: Login with SSH keys (opens new window)