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Serial Number Arithmetic (RFC1982)

IP.com Disclosure Number: IPCOM000004262D
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 6 page(s) / 13K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Elz & R. Bush: AUTHOR

Abstract

This memo defines serial number arithmetic, as used in the Domain Name System. The DNS has long relied upon serial number arithmetic, a concept which has never really been defined, certainly not in an IETF document, though which has been widely understood. This memo supplies the missing definition. It is intended to update RFC1034 and RFC1035.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 20% of the total text.

Network Working Group R. Elz

Request for Comments: 1982 University of Melbourne

Updates: 1034, 1035 R. Bush

Category: Standards Track RGnet, Inc.

August 1996

Serial Number Arithmetic

Status of this Memo

This document specifies an Internet standards track protocol for the

Internet community, and requests discussion and suggestions for

improvements. Please refer to the current edition of the "Internet

Official Protocol Standards" (STD 1) for the standardization state

and status of this protocol. Distribution of this memo is unlimited.

Abstract

This memo defines serial number arithmetic, as used in the Domain

Name System. The DNS has long relied upon serial number arithmetic,

a concept which has never really been defined, certainly not in an

IETF document, though which has been widely understood. This memo

supplies the missing definition. It is intended to update RFC1034

and RFC1035.

1. Introduction

The serial number field of the SOA resource record is defined in

RFC1035 as

SERIAL The unsigned 32 bit version number of the original copy of

the zone. Zone transfers preserve this value. This value

wraps and should be compared using sequence space

arithmetic.

RFC1034 uses the same terminology when defining secondary server zone

consistency procedures.

Unfortunately the term "sequence space arithmetic" is not defined in

either RFC1034 or RFC1035, nor do any of their references provide

further information.

This phrase seems to have been intending to specify arithmetic as

used in TCP sequence numbers [RFC793], and defined in [IEN-74].

Unfortunately, the arithmetic defined in [IEN-74] is not adequate for

the purposes of the DNS, as no general comparison operator is

defined.

To avoid further problems with this simple field, this document

defines the field and the operations available upon it. This

definition is intended merely to clarify the intent of RFC1034 and

RFC1035, and is believed to generally agree with current

implementations. However, older, superseded, implementations are

known to have treated the serial number as a simple unsigned integer,

with no attempt to implement any kind of "sequence space arithmetic",

however that may have been interpreted, and further, ignoring the

requirement that the value wraps. Nothing can be done with these

implementations, beyond extermin...