CIS 527

Lab 3 - DNS

Special Thanks

Much of this information adapted from slides by Seth Galitzer

History

• 1965 - ARPANET
• 1969 - 4 Nodes
• 1971 - 15 Nodes
• 1982 - TCP/IP Developed
• 1984 - Over 1000 Hosts
• 1987 - Over 20000 Hosts

hosts.txt

• Hosted by SRI
• Maps System Names to IP Addresses
• Updated Manually
• Difficult to Avoid Collisions
• Maintain Consistency Across Systems

Domain Name Service (DNS)

• Developed in 1983 (RFC 882-883)
• Finalized in 1987 (RFC 1035-1035)
• Distributed System of Name Servers
• Hierarchical, Consistent Name Space
• Multiple Protocols and Data Types

Image Source: Wikipedia

Image Source: Wikipedia

BIND

• Widely Used DNS Server
• Latest: BIND 9
• Implements All IETF DNS Standards

DNS Record Types

• SOA - Start of Authority
• A - IPv4 Address
• AAAA - IPv6 Address
• CNAME - Canonical Name (Alias)
• MX - Mail Exchange
• NS - Name Server
• PTR - Pointer (Reverse Lookup)
• TXT - Text