Monitor IP address that host resolves to

Hi Peter -

You're probably aware that the existing DNS datasource verifies resolution of hostname to address (from the perspective of the Collector) and alerts upon lookup failure.

If you want to track changes to a host's ip address, one could write a script datasource that does a DNS lookup, stores the resolved address in a cache file, and at each successive poll compares the currently resolved address with the cached address. In this way you could trigger an alert upon changes to DNS.