I'm Being Attacked by PRISONER.IANA.ORG!
RFC 6305

Internet Engineering Task Force (IETF)                          J. Abley
Request for Comments: 6305                                         ICANN
Category: Informational                                         W. Maton
ISSN: 2070-1721                                                 NRC-CNRC
                                                               July 2011

                I'm Being Attacked by PRISONER.IANA.ORG!

Abstract

   Many sites connected to the Internet make use of IPv4 addresses that
   are not globally unique.  Examples are the addresses designated in
   RFC 1918 for private use within individual sites.

   Hosts should never normally send DNS reverse-mapping queries for
   those addresses on the public Internet.  However, such queries are
   frequently observed.  Authoritative servers are deployed to provide
   authoritative answers to such queries as part of a loosely
   coordinated effort known as the AS112 project.

   Since queries sent to AS112 servers are usually not intentional, the
   replies received back from those servers are typically unexpected.
   Unexpected inbound traffic can trigger alarms on intrusion detection
   systems and firewalls, and operators of such systems often mistakenly
   believe that they are being attacked.

   This document provides background information and technical advice to
   those firewall operators.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6305.

Abley & Maton                 Informational                     [Page 1]
RFC 6305        I'm Being Attacked by PRISONER.IANA.ORG!       July 2011

Copyright Notice

   Copyright (c) 2011 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.

Table of Contents

   1.  Introduction and Target Audience  . . . . . . . . . . . . . . . 3
   2.  Private-Use Addresses . . . . . . . . . . . . . . . . . . . . . 3
   3.  DNS Reverse Mapping . . . . . . . . . . . . . . . . . . . . . . 3
   4.  DNS Reverse Mapping for Private-Use Addresses . . . . . . . . . 4
   5.  AS112 Nameservers . . . . . . . . . . . . . . . . . . . . . . . 4
   6.  Inbound Traffic from AS112 Servers  . . . . . . . . . . . . . . 5
   7.  Corrective Measures . . . . . . . . . . . . . . . . . . . . . . 5
   8.  AS112 Contact 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 . . . . . . . . . . . . . . . . . . 7

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RFC 6305        I'm Being Attacked by PRISONER.IANA.ORG!       July 2011

1.  Introduction and Target Audience

   Readers of this document may well have experienced an alarm from a
   firewall or an intrusion-detection system, triggered by unexpected
   inbound traffic from the Internet.  The traffic probably appeared to
   originate from one of several hosts discussed further below.

   The published contacts for those hosts may well have suggested that
   you consult this document.

   If you are following up on such an event, you are encouraged to
   follow your normal security procedures and take whatever action you
   consider to be appropriate.  This document contains information that
   may assist you.