Domain Name System
- The Domain Name System (DNS) maintains the name
(jmvidal.cse.sc.edu) to IP (129.252.11.88) mapping for all
machines in the Internet.
- It was developed as a solution to a file-sharing
problem. The /etc/hosts file got too big.
- DNS works by:
- The names form a hierarchy. USC is responsible for any
machine names of the form *.sc.edu. Each domain has an
authority.
- When a machine needs to know an IP it asks its local DNS
server.
- If the server does not know it will ask the authority
for that domain.
- Server will cache the reply when received so it will be
available for future requests. These are expirable.
José M. Vidal
.
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