Monitoring DNS for Network Issues

How to Monitor DNS (The Internet's Phonebook) (Day 17/30) Your users

type in google.com, but the page says "Server not found." The internet is up,

but nothing works. The internet's phonebook, DNS, is broken. DNS (Domain Name

System) is what translates a name like google.com into an IP address. You need to monitor

your DNS resolvers. Set up a simple "DNS query" check. Ask your internal DNS server to resolve

a common name. Measure the time it takes. A good DNS query should be less than

50 milliseconds. If it takes 2 seconds, or if it fails, you've found your problem.

Monitoring DNS ensures that "server not found" errors aren't coming from your own network.