Life of a Packet (Full Meal Deal)

Domain Name System (DNS)

• DNS resolves Fully Qualified Domain Name (FQND) to IP addresses
• Host send their DNS queries to a DNS server usually over UDP port 53
• On a PC, the Nslookup command delivers FQND to IP address
• DNS commands to set up a router client to lookup FQND
•     #> ip domain-lookup
•     #> ip name-server x.x.x.x
•     #> ip domain-name letnet.net (primary domain name)
•     #> ip domain-list letu.edu (additional DNS suffixes to search)
• Setup router as DNS server, usually done by windows server
•     #> ip dns server
•     #> ip host (hostname) x.x.x.2 (address records)
•     #> ip host (hostname.letnet.net) x.x.x.2 ; etc.