Assigned numbers
RFC 960
Document | Type |
RFC - Historic
(December 1985; No errata)
Obsoleted by RFC 990
Obsoletes RFC 943
|
|
---|---|---|---|
Authors | |||
Last updated | 2013-03-02 | ||
Stream | Legacy | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 960 (Historic) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group J. Reynolds
Request for Comments: 960 J. Postel
ISI
Obsoletes RFCs: 943, 923, 900, 870, December 1985
820, 790, 776, 770, 762, 758,
755, 750, 739, 604, 503, 433, 349
Obsoletes IENs: 127, 117, 93
ASSIGNED NUMBERS
Status of this Memo
This memo is an official status report on the numbers used in
protocols in the ARPA-Internet community. Distribution of this memo
is unlimited.
Introduction
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 Joyce Reynolds. The assignment of numbers is also handled by
Joyce. If you are developing a protocol or application that will
require the use of a link, socket, port, protocol, network number,
etc., please contact Joyce to receive a number assignment.
Joyce Reynolds
USC - Information Sciences Institute
4676 Admiralty Way
Marina del Rey, California 90292-6695
Phone: (213) 822-1511
ARPA mail: JKREYNOLDS@USC-ISIB.ARPA
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 "Internet Protocol Transition Workbook" [39] or in the old
"ARPANET Protocol Handbook" [40] prepared by the NIC. Some of the
items listed are undocumented. Further information on protocols can
be found in the memo "Official ARPA-Internet Protocols" [104].
In all cases the name and mailbox of the responsible individual is
indicated. In the lists that follow, a bracketed entry, e.g.,
[nn,iii], at the right hand margin of the page indicates a reference
for the listed protocol, where the number ("nn") cites the document
and the letters ("iii") cites the person. Whenever possible, the
letters are a NIC Ident as used in the WHOIS service.
Reynolds & Postel [Page 1]
Assigned Numbers RFC 960
Network Numbers
ASSIGNED NETWORK NUMBERS
The network numbers listed here are used as internet addresses by the
Internet Protocol (IP) [39,92]. The IP uses a 32-bit address field
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 of address, or class A, has a 7-bit network number
and a 24-bit local address. The highest-order bit is set to 0.
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 of address, class B, has a 14-bit network number
and a 16-bit local address. The two highest-order bits are set to
1-0. This allows 16,384 class B 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 0| NETWORK | Local Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Class B Address
The third type of address, class C, has a 21-bit network number
and a 8-bit local address. The three highest-order bits are set
to 1-1-0. This allows 2,097,152 class C 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 1 0| NETWORK | Local Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Class C Address
Note: No addresses are allowed with the three highest-order bits
set to 1-1-1. These addresses (sometimes called "class D") are
reserved.
Reynolds & Postel [Page 2]
Assigned Numbers RFC 960
Network Numbers
One commonly used notation for internet host addresses divides the
32-bit address into four 8-bit fields and specifies the value of each
field as a decimal number with the fields separated by periods. This
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