Common Protocols Multicast Addresses Ethernet Numbers Tech Essays Internet Course Solaris Information Misc. IDS Sniffers Vulnerability Scanners Port Scanners Network Monitoring Firewall Ping NetBIOS Password Packet Tools Promiscuous Detection Fingerprinting Phone Steganography HTML NT Misc. The telephone company solves this problem with lots of large paper directories, and operators you call and ask about numbers not in your directory. Internet solves this problem with a hierarchy of simple, mnenomic names, called domain names .
Some people think the dots in a domain name correspond to the dots in the numeric address.
This is not the case. There are always three periods in an IP address, separating its four constituent bytes. There are a variable number of periods in a domain name. The crucial DNS documentation is provided in RFC 1034 and RFC 1035 . The Encyclopedia's Programmed Instruction Course has a DNS Section , and the Encyclopedia's software section has a Dig page , discussing use of this free software diagnostic tool.