Systemd is ideally suited for this.

Create a service file /etc/systemd/system/sshtunnel.service containing:

[Unit]
Description=SSH Tunnel
After=network.target

[Service]
Restart=always
RestartSec=20
User=sshtunnel
ExecStart=/bin/ssh -NT -o ServerAliveInterval=60 -L 5900:localhost:5900 user@otherserver

[Install]
WantedBy=multi-user.target

(Modify the ssh command to suit)

• this will run as user sshtunnel so make sure that user exists first
• issue systemctl enable sshtunnel to set it to start at boot time
• issue systemctl start sshtunnel to start immediately

Systemd is ideally suited for this.

Create a service file /etc/systemd/system/sshtunnel.service containing:

[Unit]
Description=SSH Tunnel
After=network.target

[Service]
Restart=always
RestartSec=20
User=sshtunnel
ExecStart=/bin/ssh -NT -o ServerAliveInterval=60 -L 5900:localhost:5900 user@otherserver

[Install]
WantedBy=multi-user.target

(Modify the ssh command to suit)

• this will run as user sshtunnel so make sure that user exists first
• issue systemctl enable sshtunnel to set it to start at boot time
• issue systemctl start sshtunnel to start immediately

Update Jan 2018: some distros (e.g. Fedora 27) may use SELinux policy to prevent the use of SSH from systemd init, in which case a custom policy will need to be created to provide the necessary exemptions.