I want PRTG to use an HTTPS sensor to monitor a particular firewall. In my PRTG configuration, I have two servers, a primary and a failover. Normally, both servers are able to see the sensor just fine. When we have problems with one of our firewalls, one of the PRTG servers can see the sensor and the other can't.
I've got a trigger set to phone a support number, but it doesn't do that unless both PRTG monitoring servers can't see the sensor. I want PRTG to be able act on the PRTG call support option if only 1 of the two PRTG monitoring servers fails to see the sensor.
How can I make this happen?