DNS NSAP RRs
DNS records to store and look up addresses from non-IP networks.
Manning, B., "DNS NSAP RRs", RFC 1348, DOI 10.17487/RFC1348, July 1992, <https://www.rfc-editor.org/info/rfc1348>.
@misc{rfc1348,
series = {Request for Comments},
number = 1348,
howpublished = {RFC 1348},
publisher = {RFC Editor},
doi = {10.17487/RFC1348},
url = {https://www.rfc-editor.org/info/rfc1348},
author = {B. Manning},
title = {{DNS NSAP RRs}},
pagetotal = 4,
year = 1992,
month = jul,
} RFC text
Contents
Network Working Group B. Manning
Request for Comments: 1348 Rice University
Updates: RFCs 1034, 1035 July 1992
DNS NSAP RRs
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. Discussion and suggestions for improvement are requested.
Please refer to the current edition of the "IAB Official Protocol
Standards" for the standardization state and status of this protocol.
Distribution of this memo is unlimited.
Table of Contents
Introduction ..................................................... 1
Background ....................................................... 1
NSAP RR .......................................................... 2
NSAP-PTR RR ...................................................... 2
REFERENCES and BIBLIOGRAPHY ...................................... 3
Security Considerations .......................................... 4
Author's Address ................................................. 4
Introduction
This RFC defines the format of two new Resource Records (RRs) for the
Domain Name System (DNS), and reserves corresponding DNS type
mnemonic and numerical codes. This format may be used with the any
proposal that has variable length addresses, but is targeted for CLNP
use.
This memo assumes that the reader is familiar with the DNS [3,4].
Background
This section describes an experimental representation of NSAP
addresses in the DNS. There are several reasons to take this approch.
First, it provides simple documentation of the correct addresses to
use in static configurations of CLNP compliant hosts and routers.
NSAP support requires that a new DNS resource record entry type
("NSAP") be defined, to store longer Internet (i.e., NSAP) addresses.
This resource record allows mapping from DNS names to NSAP addresses,
and will contain entries for systems which are able to run Internet
applications, over TCP or UDP, over CLNP.
The backward translation (from NSAP address to DNS name) is
facilitated by definition of an associated resource record. This
resource record is known as "NSAP-PTR", and is used in a manner
analogous to the existing "in-addr.arpa".
These RRs are intended for use in a proposal [6] by one of the
members of the NOOP WG to address the next-generation internet.
The NSAP RR
The NSAP RR is defined with mnemonic NSAP and type code 22 (decimal).
An NSAP (Network Service Access Protocol) number is a unique string
to OSI transport service.
The numbering plan follows RFC 1237 and associated OSI definitions
for NSAP format.
NSAP has the following format:
<owner> <ttl> <class> NSAP <length> <NSAP-address>
All fields are required.
<length> identifies the number of octets in the <NSAP-address> as
defined by the various national and international authorities.
<NSAP-address> enumerates the actual octet values assigned by the
assigning authority. Its format in master files is a <character-
string> syntactically identical to that used in TXT and HINFO.
The format of NSAP is class insensitive. NSAP RR causes no
additional section processing.
For example:
foo.bar.com. IN NSAP 21 47000580ffff000000321099991111222233334444
host.school.de IN NSAP 17 39276f3100111100002222333344449876
The RR data is the ASCII representation of the digits. It is encoded
as two <character-strings>, i.e., count followed by characters.
The NSAP-PTR RR
The NSAP-PTR RR is defined with mnemonic NSAP-PTR and a type code 23
(decimal).
Its function is analogous to the PTR record used for IP addresses
[4,7].
NSAP-PTR has the following format:
<NSAP-suffix> <ttl> <class> NSAP-PTR <owner>
All fields are required.
<NSAP-suffix> enumerates the actual octet values assigned by the
assigning authority for the LOCAL network. Its format in master
files is a <character-string> syntactically identical to that used in
TXT and HINFO.
The format of NSAP-PTR is class insensitive. NSAP-PTR RR causes no
additional section processing.
For example:
In net ff08000574.nsap-in-addr.arpa:
444433332222111199990123000000ff NSAP-PTR foo.bar.com.
Or in net 11110031f67293.nsap-in-addr.arpa:
67894444333322220000 NSAP-PTR host.school.de.
The RR data is the ASCII representation of the digits. It is encoded
as a <character-string>.
REFERENCES and BIBLIOGRAPHY
[1] Stahl, M., "Domain Administrators Guide", RFC 1032, Network
Information Center, SRI International, November 1987.
[2] Lottor, M., "Domain Administrators Operations Guide", RFC 1033,
Network Information Center, SRI International, November, 1987.
[3] Mockapetris, P., "Domain Names - Concepts and Facilities", RFC
1034, USC/Information Sciences Institute, November 1987.
[4] Mockapetris, P., "Domain Names - Implementation and
Specification", RFC 1035, USC/Information Sciences Institute,
November 1987.
[5] Colella, R., Gardner, E., and R. Callon, "Guidelines for OSI
NSAP Allocation in the Internet", RFC 1237, NIST, Mitre, DEC,
July 1991.
[6] Callon, R., "TCP and UDP with Bigger Addresses (TUBA),
A Simple Proposal for Internet Addressing and Routing",
Digital Equipment Corporation, RFC 1347, June 1992.
[7] Mockapetris, P., "DNS Encoding of Network Names and Other Types",
RFC 1101, USC/Information Sciences Institute, April 1989.
[8] ISO/IEC. Information Processing Systems -- Data Communications
-- Network Service Definition Addendum 2: Network Layer Address-
ing. International Standard 8348/Addendum 2, ISO/IEC JTC 1,
Switzerland, 1988.
[9] Bryant, P., "NSAPs", PB660, IPTAG/92/23, SCIENCE AND ENGINEERING
RESEARCH COUNCIL, RUTHERFORD APPLETON LABORATORY May 1992.
Security Considerations
Security issues are not addressed in this memo.
Author's Address
Bill Manning
Rice University - ONCS
PO Box 1892
6100 South Main
Houston, Texas 77251-1892
Phone: +1.713.285.5415
EMail: bmanning@rice.edu
AI ELI5
On this page
§1Why DNS Needs NSAP Records
RFC 1348 defines two new DNS resource record types to extend the Domain Name System beyond IP addresses. Some systems want to run Internet applications (TCP and UDP) on top of CLNP (the OSI Connectionless Network Protocol), which uses NSAP (Network Service Access Point) addresses instead of 32-bit IP addresses. DNS needs a way to store these longer addresses and allow reverse lookup.
Some computers use a different numbering system for addresses, and DNS needs to be able to write them down and look them up.
§2The NSAP and NSAP-PTR Record Types
The NSAP resource record (type code 22) stores the actual NSAP address. It has the form <owner> <ttl> <class> NSAP <length> <NSAP-address>. The length field specifies the number of octets in the NSAP address, which varies by the national and international authority that assigned it. The address itself is encoded as a character string.
The NSAP-PTR record (type code 23) provides the reverse function, similar to the IPv4 PTR records in in-addr.arpa. It maps from an NSAP suffix back to a DNS name, allowing reverse lookups in a domain tree analogous to nsap-in-addr.arpa.
NSAP stores an address from another network system, and NSAP-PTR does the reverse, finding the name when you start with the address.
§3Purpose and Status
This RFC was designed to support a next-generation Internet protocol proposal that would use longer addresses. The two record types provide the infrastructure for DNS to work with CLNP and other OSI-based systems. The RFC updates RFC 1034 and RFC 1035, the core DNS specifications.
These new DNS records were made for an experimental new version of the Internet that never became the main one, but they laid groundwork for DNS to handle different address types.