The Domain Name System (DNS) translates names people remember, like www.example.com, into IP addresses computers use. Almost every connection starts with a DNS lookup, so when DNS fails, users say 'the internet is down' even though the network is fine; a quick test is whether you can reach a site by IP address but not by name. DNS uses port 53, UDP for most queries and TCP for zone transfers and large responses. Network+ tests record types, how resolution works, zone concepts and DNS security.
Free account
Keep reading for free
Create a free StudyToCert account to read the rest of this lesson: 7 more sections, 7 key terms, a real-world example, an exam tip and self-check questions. Every lesson, lab and practice test is free with an account.