Compacted-DNS (C-DNS): A Format for DNS Packet Capture
RFC 8618

Document Type RFC - Proposed Standard (September 2019; No errata)
Last updated 2019-09-03
Replaces draft-dickinson-dnsop-dns-capture-format
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Stream WG state Submitted to IESG for Publication
Document shepherd Tim Wicinski
Shepherd write-up Show (last changed 2018-10-02)
IESG IESG state RFC 8618 (Proposed Standard)
Consensus Boilerplate Yes
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Responsible AD Warren Kumari
Send notices to Tim Wicinski <tjw.ietf@gmail.com>
IANA IANA review state IANA OK - Actions Needed
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Internet Engineering Task Force (IETF)                      J. Dickinson
Request for Comments: 8618                                      J. Hague
Category: Standards Track                                   S. Dickinson
ISSN: 2070-1721                                               Sinodun IT
                                                            T. Manderson
                                                                   ICANN
                                                                 J. Bond
                                              Wikimedia Foundation, Inc.
                                                          September 2019

         Compacted-DNS (C-DNS): A Format for DNS Packet Capture

Abstract

   This document describes a data representation for collections of DNS
   messages.  The format is designed for efficient storage and
   transmission of large packet captures of DNS traffic; it attempts to
   minimize the size of such packet capture files but retain the full
   DNS message contents along with the most useful transport metadata.
   It is intended to assist with the development of DNS traffic-
   monitoring applications.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc8618.

Dickinson, et al.            Standards Track                    [Page 1]
RFC 8618         C-DNS: A Format for DNS Packet Capture   September 2019

Copyright Notice

   Copyright (c) 2019 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
   (https://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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Data Collection Use Cases . . . . . . . . . . . . . . . . . .   5
   4.  Design Considerations . . . . . . . . . . . . . . . . . . . .   8
   5.  Choice of CBOR  . . . . . . . . . . . . . . . . . . . . . . .  10
   6.  C-DNS Format Conceptual Overview  . . . . . . . . . . . . . .  10
     6.1.  Block Parameters  . . . . . . . . . . . . . . . . . . . .  14
     6.2.  Storage Parameters  . . . . . . . . . . . . . . . . . . .  14
       6.2.1.  Optional Data Items . . . . . . . . . . . . . . . . .  15
       6.2.2.  Optional RRs and OPCODEs  . . . . . . . . . . . . . .  16
       6.2.3.  Storage Flags . . . . . . . . . . . . . . . . . . . .  17
       6.2.4.  IP Address Storage  . . . . . . . . . . . . . . . . .  17
   7.  C-DNS Format Detailed Description . . . . . . . . . . . . . .  18
     7.1.  Map Quantities and Indexes  . . . . . . . . . . . . . . .  18
     7.2.  Tabular Representation  . . . . . . . . . . . . . . . . .  18
     7.3.  "File"  . . . . . . . . . . . . . . . . . . . . . . . . .  19
       7.3.1.  "FilePreamble"  . . . . . . . . . . . . . . . . . . .  20
         7.3.1.1.  "BlockParameters" . . . . . . . . . . . . . . . .  20
           7.3.1.1.1.  "StorageParameters" . . . . . . . . . . . . .  21
             7.3.1.1.1.1.  "StorageHints"  . . . . . . . . . . . . .  22
           7.3.1.1.2.  "CollectionParameters"  . . . . . . . . . . .  24
       7.3.2.  "Block" . . . . . . . . . . . . . . . . . . . . . . .  25
         7.3.2.1.  "BlockPreamble" . . . . . . . . . . . . . . . . .  26
         7.3.2.2.  "BlockStatistics" . . . . . . . . . . . . . . . .  27
         7.3.2.3.  "BlockTables" . . . . . . . . . . . . . . . . . .  28
           7.3.2.3.1.  "ClassType" . . . . . . . . . . . . . . . . .  29
           7.3.2.3.2.  "QueryResponseSignature"  . . . . . . . . . .  30
           7.3.2.3.3.  "Question"  . . . . . . . . . . . . . . . . .  33
           7.3.2.3.4.  "RR"  . . . . . . . . . . . . . . . . . . . .  34
           7.3.2.3.5.  "MalformedMessageData"  . . . . . . . . . . .  34

Dickinson, et al.            Standards Track                    [Page 2]
RFC 8618         C-DNS: A Format for DNS Packet Capture   September 2019

         7.3.2.4.  "QueryResponse" . . . . . . . . . . . . . . . . .  35
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