Hi Ming,
there’s no native “site connection lost” alert in Checkmk, but the standard solution is straightforward: create a regular host on your HQ central site representing each branch’s Checkmk server.
On the central site:
- Create a host with the IP of the branch Checkmk server
- Set “Monitored from” → central site
- If you only want reachability: set “Checkmk agent / API integration” → “No agent, no API”
- Set up a normal notification rule for this host → you’ll be alerted when it goes CRIT
If HQ can reach the branch directly (e.g. VPN): use a regular ping check as the host check command.
If only the Livestatus port is forwarded: go to Setup > Host monitoring rules > Host check command, select “TCP connection” and point it to port 6557.
This approach is described and confirmed working by other users here:
- Distributed Environment monitor remote sites status
- Setting Up Remote Site Status Monitoring & Notifications in Distributed Monitoring
Note for Raw Edition: centralized notification forwarding from branch to HQ requires the Notification Spooler, which is an Enterprise feature. In Raw, each site sends its own notifications independently — even when the connection to HQ is down. More details: Distributed monitoring - Scaling and distributing Checkmk
Bernd