a distributed database that maps domain names to IP addresses using a series of distributed DNS servers.
TLD = top-level domain like .com, .net, .us, .cn
second level: cnn.com, google.com
machine level: www.cnn.com, foo.google.com
caching on local box, then dns server
Root server, 13 root servers have globally well-known IP addressesRegistrar
Authority, can set TTL, propagation delay
TTL: forcing another look up. DNS used for load balancing
DNS Cache poisoning. Spoofing with paypa1.com vs paypa1.com. Unicode issues: "o" in a foreign language looks like zero in english. micr0s0ft.com
DNS is a strategic national concern for all nations, which is why other countries want the root servers to become managed by the UN. Currently managed by the US Department of Commerce.
To register new domain: