Skip to main content

RFC 2181 - Clarifications to the DNS Specification

  • Status: Proposed Standard
  • Published: July 1997
  • Stream: IETF
  • Updates: RFC 1034, RFC 1035, RFC 1123
  • Errata: No Errata

Document Information​

  • RFC Number: 2181
  • Title: Clarifications to the DNS Specification
  • Authors: R. Elz (University of Melbourne), R. Bush (RGnet, Inc.)
  • Date: July 1997
  • Category: Standards Track
  • Updates: RFC 1034, RFC 1035, RFC 1123

Abstract​

This document considers some areas that have been identified as problems with the specification of the Domain Name System, and proposes remedies for the defects identified. Eight separate issues are considered:

  • IP packet header address usage from multi-homed servers,
  • TTLs in sets of records with the same name, class, and type,
  • correct handling of zone cuts,
  • three minor issues concerning SOA records and their use,
  • the precise definition of the Time to Live (TTL)
  • Use of the TC (truncated) header bit
  • the issue of what is an authoritative, or canonical, name,
  • and the issue of what makes a valid DNS label.

The first six of these are areas where the correct behaviour has been somewhat unclear, we seek to rectify that. The other two are already adequately specified, however the specifications seem to be sometimes ignored. We seek to reinforce the existing specifications.

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.

Table of Contents​