Returning multiple answers in DNS responses.
draft-wkumari-dnsop-multiple-responses-02

The information below is for an old version of the document
Document Type Active Internet-Draft (individual)
Last updated 2016-01-05
Stream (None)
Intended RFC status (None)
Formats pdf htmlized (tools) htmlized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date
Responsible AD (None)
Send notices to (None)
dnsop                                                          W. Kumari
Internet-Draft                                                    Google
Intended status: Standards Track                                  Z. Yan
Expires: July 8, 2016                                              CNNIC
                                                             W. Hardaker
                                                           Parsons, Inc.
                                                        January 05, 2016

              Returning multiple answers in DNS responses.
               draft-wkumari-dnsop-multiple-responses-02

Abstract

   This document (re)introduces the ability to provide multiple answers
   in a DNS response.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 8, 2016.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Kumari, et al.            Expires July 8, 2016                  [Page 1]
Internet-Draft            DNS Multiple Answers              January 2016

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements notation . . . . . . . . . . . . . . . . . .   3
   2.  Background  . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Returning multiple answers  . . . . . . . . . . . . . . . . .   3
   5.  Additional records pseudo-RR  . . . . . . . . . . . . . . . .   5
     5.1.  File Format . . . . . . . . . . . . . . . . . . . . . . .   5
     5.2.  Wire Format . . . . . . . . . . . . . . . . . . . . . . .   5
   6.  Signaling support . . . . . . . . . . . . . . . . . . . . . .   6
   7.  Stub-Resolver Considerations  . . . . . . . . . . . . . . . .   6
   8.  Use of Additional information . . . . . . . . . . . . . . . .   6
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   10. Security Considerations . . . . . . . . . . . . . . . . . . .   7
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     12.1.  Normative References . . . . . . . . . . . . . . . . . .   7
     12.2.  Informative References . . . . . . . . . . . . . . . . .   8
   Appendix A.  Changes / Author Notes.  . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   Often the name being resolved in the DNS provides information about
   why the name is being resolved, allowing the nameserver to predict
   what other answers the client will soon query for.  By providing
   multiple answers in the response, the authoritative name server
   operator can ensure that the recursive server that the client is
   using has all the answers in its cache.

   For example, the name server operator of Example Widgets, Inc
   (example.com) knows that the example.com web page at www.example.com
   contains various other resources, including some images (served from
   images.example.com), some Cascading Style Sheets (served from
   css.example.com) and some JavaScript (data.example.com).  A client
   attempting to resolve www.example.com is very likely to be a web
   browser rendering the page and so will need to also resolve all of
   the other names to obtain these other resources.  Providing all of
   these answers in response to a query for www.example.com allows the
   recursive server to populate its cache and have all of the answers
   available when the client asks for them.

   Other examples where this technique is useful include SMTP (including
   the mail server address when serving the MX record), SRV (providing
   the target information in addition to the SRV response) and TLSA
Show full document text