Background

• The Internet Domain Name System is a very large distributed database

• It is used to translate domain names to IP addresses

• • www.nwu.edu -> 129.105.212.72
  • And vice versa…

• Some domain names map to multiple IP addresses

• • www.yahoo.com -> 204.71.200.74, 204.71.200.75
  • E.g., multiple servers, load balancing

• Some IP addresses map to multiple domain names

• • 169.237.6.7 -> www.cs.ucdavis.edu, chaos.cs.ucdavis.edu
  • E.g., aliasing of a web server

• Some domain names are virtual

• • www.borella.net
  • Maps to an IP address, but the host is shared