DNS lookup from the local host

1. If the IP address is cached on the local host, it will use this.
2. The OS initiates a DNS lookup request to a preconfigured DNS resolver. This message is typically (but not always) sent via Universal datagram protocol (UDP).
3. The lookup request is propagated across the network to the DNS resolver.
4. (Step 4 is encapsulated in the DNS resolver page.)
5. The DNS resolver creates a return TCP/UDP message, which is propagated back to the OS.