Assigned numbers (RFC0790)
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2000-Sep-13
Internet Society Requests For Comment (RFCs)
Network Working Group J. Postel
Request for Comments: 790 ISI
Obsoletes RFCs: 776, 770, 762, 758,
755, 750, 739, 604, 503, 433, 349
Obsoletes IENs: 127, 117, 93
This Network Working Group Request for Comments documents the currently
assigned values from several series of numbers used in network protocol
implementations. This RFC will be updated periodically, and in any case
current information can be obtained from Jon Postel. The assignment of
numbers is also handled by Jon. If you are developing a protocol or
application that will require the use of a link, socket, port, protocol,
or network number please contact Jon to receive a number assignment.
USC - Information Sciences Institute
4676 Admiralty Way
Marina del Rey, California 90291
phone: (213) 822-1511
ARPANET mail: POSTEL@ISIF
Most of the protocols mentioned here are documented in the RFC series of
notes. The more prominent and more generally used are documented in the
Protocol Handbook  prepared by the Network Information Center (NIC).
Some of the items listed are undocumented. In all cases the name and
mailbox of the responsible individual is indicated. In the lists that
follow, a bracketed entry, e.g., [17,iii], at the right hand margin of
the page indicates a reference for the listed protocol, where the number
cites the document and the "iii" cites the person.
RFC 790 September 1981
ASSIGNED NETWORK NUMBERS
This list of network numbers is used in the internet address .
The Internet Protocol (IP) uses a 32 bit address and divides that
address into a network part and a "rest" or local address part. The
division takes 3 forms or classes.
The first type, or class a, of address has a 7-bit network number
and a 24-bit local address. This allows 128 class a networks.
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|0| NETWORK | Local Address |
Class A Address
The second type, or class b, of address has a 14-bit network
number and a 16-bit loca...