DNS - Domain Name Service (5)
BIND - Berkeley Internet Name Domain - most common DNS
DNS is a distributed database that resides on different domain servers. There are primary, secondary, and cash-only servers
- Primary DNS server keeps the master copy of the entire (local) database both in memory and on disk
- Secondary DNS server obtains a copy of the database from the primary server
- Cash-only server: runs the name server software, but keeps no nameserver database files
DNS server can provide lots of information about a network (nodes, operating system, people responsible, mail servers)
DNS can provide “unwanted “ information for
- hackers
- vendors’ sales representatives
- outside agents