DNS servers monitoring
A few months ago, I found myself needing to know about the reliability of some internal DNS provider’s servers, after getting a series of hardly trackable random network issues, aka “It’s always DNS”. More specifically, I needed to know about the following: number of errors/timeouts capability to query over TCP or UDP capability to monitor multiple DNS servers at once return codes received in the answer (i.e. NOERROR, SERVFAIL, NXDOMAIN, you name it) ...