DNS [Domain Name System] is a hierarchical naming system for internet hosts. It serves as a sort of “phone book” for the Internet so hosts can be referred to by meaningful names instead of by IP addresses. DNS provides both forward and reverse name mapping (fs0.ece.cmu.edu is 220.127.116.11 and 18.104.22.168 is fs0.ece.cmu.edu).
DNS is a distributed database, and servers exist within each domain to handle local tasks. Those servers are usually “authoritative” for their domain.
There are three types of DNS servers: primary, secondary (or slaves) and caching. In general the configuration information is entered into the primary DNS server for a domain and then distributed to the other servers. This is done partially to allow for load balancing and partially to restrict access to those servers likely to be compromised by an attack on DNS itself.
The names of the accessible DNS servers for ECE.CMU.EDU are:
This information is automatically distributed by DHCP. Note: these name servers are authoritative for: