RFC 1386 (rfc1386) - Page 2 of 31
The US Domain
Alternative Format: Original Text Document
RFC 1386 The US Domain December 1992
1. INTRODUCTION
1.1 The Internet Domain Name System
The Domain Name System (DNS) provides for the translation between
host names and addresses. Within the Internet, this means
translating from a name such as "venera.isi.edu", to an IP address
such as "128.9.0.32". The DNS is a set of protocols and databases.
The protocols define the syntax and semantics for a query language to
ask questions about information located by DNS-style names. The
databases are distributed and replicated. There is no dependence on
a single central server, and each part of the database is provided in
at least two servers.
The assignment of the 32-bit IP addresses is a separate activity. IP
addresses are assigned by the Network Information Center
().
In addition to translating names to addresses for hosts that are on
the Internet, the DNS provides for registering DNS-style names for
other hosts reachable (via electronic mail) through gateways or mail
relays. The records for such name registration point to an Internet
host (one with an IP address) that acts as a mail forwarder for the
registered host. For example, the host "bah.rochester.ny.us" is
registered in the DNS with a pointer to the mail relay
"relay1.uu.net". This type of pointer is called an MX record.
This gives electronic mail users a uniform mail addressing syntax and
avoids making users aware of the underlying network boundaries.
The reason for the development of the domain system was growth in the
Internet. The host name to address mappings were maintained by the
Network Information Center (NIC) in a single file, called HOSTS.TXT,
which was FTPed by all the hosts on the Internet. The network
population was changing in character. The timeshared hosts that made
up the original ARPANET were being replaced with local networks of
workstations. Local organizations were administering their own names
and addresses, but had to wait for the NIC to make changes in
HOSTS.TXT to make the changes visible to the Internet at large.
Organizations also wanted some local structure on the name space.
The applications on the Internet were getting more sophisticated and
creating a need for general purpose name service. The idea of a
hierarchical name space, with the hierarchy roughly corresponding to
organizational structure, and names using "." as the character to
mark the boundary between hierarcy levels. A design using a
distributed database and generalized resources was implemented.
The domain system provides standard formats for resource data,
Cooper & Postel