How to create service that will execute periodically bash script (with ssh connection)

Question

I am having bash script that checks for ssh connection in lsof. In case it's down, it will open it once again.

I found some information how to create service that starts periodically, but the problem is, that whenever it will start service, and run ssh connection, after exit of service this connection dies.

I know that there is an option RemainAfterExit=yes, but it will remain service active after execution.

So in nutshell:

1. I want to start bash script periodically
2. script checks for ssh
3. If tunnel is down, it will start it (and leave it in system)
4. Service needs to start once again run script for ssh check

My service configuration:

[Unit]
Description=Periodically check for ssh tunnel
After=network.target

[Service]
Type=simple
Restart=always
RestartSec=30
User=root
ExecStart=/bin/bash /opt/script.sh -s

[Install]
WantedBy=sysinit.target

EDIT:

In my script with -s parameter I am just calling function which is checking if ssh tunnel is established for particular address, and if no, it'll just open it using standard ssh.

if [[ $(sudo lsof -i -n | egrep '\<ssh\>' | grep "$ip" | wc -l) -gt 0 ]]; then
            INFO "Tunnel is established for IP "$ip"."
            exit 0
else
            ERROR "Tunnel for IP "$ip" has been disconnected. Trying to reconnect."
            ssh -fN [email protected]
fi