DoD Internet host table specification
RFC 952
| Document | Type |
RFC - Unknown
(October 1985; Errata)
Updated by RFC 1123
Obsoletes RFC 810
|
|
|---|---|---|---|
| Last updated | 2013-04-10 | ||
| Stream | Legacy | ||
| Formats | plain text pdf html bibtex | ||
| Stream | Legacy state | (None) | |
| Consensus Boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | RFC 952 (Unknown) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group K. Harrenstien (SRI)
Request for Comments: 952 M. Stahl (SRI)
E. Feinler (SRI)
Obsoletes: RFC 810, 608 October 1985
DOD INTERNET HOST TABLE SPECIFICATION
STATUS OF THIS MEMO
This RFC is the official specification of the format of the Internet
Host Table. This edition of the specification includes minor
revisions to RFC-810 which brings it up to date. Distribution of this
memo is unlimited.
INTRODUCTION
The DoD Host Table is utilized by the DoD Hostname Server maintained
by the DDN Network Information Center (NIC) on behalf of the Defense
Communications Agency (DCA) [See RFC-953].
LOCATION OF THE STANDARD DOD ONLINE HOST TABLE
A machine-translatable ASCII text version of the DoD Host Table is
online in the file NETINFO:HOSTS.TXT on the SRI-NIC host. It can be
obtained via FTP from your local host by connecting to host
SRI-NIC.ARPA (26.0.0.73 or 10.0.0.51), logging in as user =
ANONYMOUS, password = GUEST, and retrieving the file
"NETINFO:HOSTS.TXT". The same table may also be obtained via the NIC
Hostname Server, as described in RFC-953. The latter method is
faster and easier, but requires a user program to make the necessary
connection to the Name Server.
ASSUMPTIONS
1. A "name" (Net, Host, Gateway, or Domain name) is a text string up
to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus
sign (-), and period (.). Note that periods are only allowed when
they serve to delimit components of "domain style names". (See
RFC-921, "Domain Name System Implementation Schedule", for
background). No blank or space characters are permitted as part of a
name. No distinction is made between upper and lower case. The first
character must be an alpha character. The last character must not be
a minus sign or period. A host which serves as a GATEWAY should have
"-GATEWAY" or "-GW" as part of its name. Hosts which do not serve as
Internet gateways should not use "-GATEWAY" and "-GW" as part of
their names. A host which is a TAC should have "-TAC" as the last
part of its host name, if it is a DoD host. Single character names
or nicknames are not allowed.
2. Internet Addresses are 32-bit addresses [See RFC-796]. In the
Harrenstien & Stahl & Feinler [Page 1]
RFC 952 October 1985
DOD INTERNET HOST TABLE SPECIFICATION
host table described herein each address is represented by four
decimal numbers separated by a period. Each decimal number
represents 1 octet.
3. If the first bit of the first octet of the address is 0 (zero),
then the next 7 bits of the first octet indicate the network number
(Class A Address). If the first two bits are 1,0 (one,zero), then
the next 14 bits define the net number (Class B Address). If the
first 3 bits are 1,1,0 (one,one,zero), then the next 21 bits define
the net number (Class C Address) [See RFC-943].
This is depicted in the following diagram:
+-+------------+--------------+--------------+--------------+
|0| NET <-7-> | LOCAL ADDRESS <-24-> |
+-+------------+--------------+--------------+--------------+
+---+----------+--------------+--------------+--------------+
|1 0| NET <-14-> | LOCAL ADDRESS <-16-> |
+---+----------+--------------+--------------+--------------+
+-----+--------+--------------+--------------+--------------+
|1 1 0| NET <-21-> | LOCAL ADDRESS|
+-----+--------+--------------+--------------+--------------+
4. The LOCAL ADDRESS portion of the internet address identifies a
host within the network specified by the NET portion of the address.
5. The ARPANET and MILNET are both Class A networks. The NET portion
is 10 decimal for ARPANET, 26 decimal for MILNET, and the LOCAL
ADDRESS maps as follows: the second octet identifies the physical
host, the third octet identifies the logical host, and the fourth
identifies the Packet Switching Node (PSN), formerly known as an
Interface Message Processor (IMP).
+-+------------+--------------+--------------+--------------+
|0| 10 or 26 | HOST | LOGICAL HOST | PSN (IMP) |
+-+------------+--------------+--------------+--------------+
(NOTE: RFC-796 also describes the local address mappings for
several other networks.)
6. It is the responsibility of the users of this host table to
translate it into whatever format is needed for their purposes.
7. Names and addresses for DoD hosts and gateways will be negotiated
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