Network Working Group                                           J. Abley
Internet-Draft                                                     ICANN
Intended status: Informational                                  W. Maton
Expires: May 16, 2011                                           NRC-CNRC
                                                       November 12, 2010


                      AS112 Nameserver Operations
                     draft-ietf-dnsop-as112-ops-06

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.

   Devices in such environments may occasionally originate Domain Name
   System (DNS) queries (so-called "reverse lookups") corresponding to
   those private-use addresses.  Since the addresses concerned have only
   local significance, it is good practice for site administrators to
   ensure that such queries are answered locally.  However, it is not
   uncommon for such queries to follow the normal delegation path in the
   public DNS instead of being answered within the site.

   It is not possible for public DNS servers to give useful answers to
   such queries.  In addition, due to the wide deployment of private-use
   addresses and the continuing growth of the Internet, the volume of
   such queries is large and growing.  The AS112 project aims to provide
   a distributed sink for such queries in order to reduce the load on
   the root and IN-ADDR.ARPA authoritative servers.  The AS112 project
   is named after the Autonomous System Number (ASN) that was assigned
   to it.

   This document describes the steps required to install a new AS112
   node, and offers advice relating to such a node's operation.

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



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   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 May 16, 2011.

Copyright Notice

   Copyright (c) 2010 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.

   This document may contain material from IETF Documents or IETF
   Contributions published or made publicly available before November
   10, 2008.  The person(s) controlling the copyright in some of this
   material may not have granted the IETF Trust the right to allow
   modifications of such material outside the IETF Standards Process.
   Without obtaining an adequate license from the person(s) controlling
   the copyright in such materials, this document may not be modified
   outside the IETF Standards Process, and derivative works of it may
   not be created outside the IETF Standards Process, except to format
   it for publication as an RFC or to translate it into languages other
   than English.




















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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  AS112 DNS Service  . . . . . . . . . . . . . . . . . . . . . .  5
     2.1.  Zones  . . . . . . . . . . . . . . . . . . . . . . . . . .  5
     2.2.  Nameservers  . . . . . . . . . . . . . . . . . . . . . . .  5
   3.  Installation of a New Node . . . . . . . . . . . . . . . . . .  6
     3.1.  Useful Background Knowledge  . . . . . . . . . . . . . . .  6
     3.2.  Topological Location . . . . . . . . . . . . . . . . . . .  6
     3.3.  Operating System and Host Considerations . . . . . . . . .  6
     3.4.  Routing Software . . . . . . . . . . . . . . . . . . . . .  7
     3.5.  DNS Software . . . . . . . . . . . . . . . . . . . . . . .  8
     3.6.  Testing a Newly-Installed Node . . . . . . . . . . . . . . 12
   4.  Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     4.1.  Monitoring . . . . . . . . . . . . . . . . . . . . . . . . 13
     4.2.  Downtime . . . . . . . . . . . . . . . . . . . . . . . . . 13
     4.3.  Statistics and Measurement . . . . . . . . . . . . . . . . 13
   5.  Communications . . . . . . . . . . . . . . . . . . . . . . . . 14
   6.  On the Future of AS112 Nodes . . . . . . . . . . . . . . . . . 15
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 16
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 17
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 19
     10.2. Informative References . . . . . . . . . . . . . . . . . . 19
   Appendix A.  History . . . . . . . . . . . . . . . . . . . . . . . 21
   Appendix B.  Change History  . . . . . . . . . . . . . . . . . . . 22
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23























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1.  Introduction

   Many sites connected to the Internet make use of IPv4 addresses that
   are not globally unique.  Examples are the addresses designated in
   [RFC1918] for private use within individual sites.

   Devices in such environments may occasionally originate Domain Name
   System (DNS) [RFC1034] queries (so-called "reverse lookups")
   corresponding to those private-use addresses.  Since the addresses
   concerned have only local significance, it is good practice for site
   administrators to ensure that such queries are answered locally
   [I-D.ietf-dnsop-default-local-zones].  However, it is not uncommon
   for such queries to follow the normal delegation path in the public
   DNS instead of being answered within the site.

   It is not possible for public DNS servers to give useful answers to
   such queries.  In addition, due to the wide deployment of private-use
   addresses and the continuing growth of the Internet, the volume of
   such queries is large and growing.  The AS112 project aims to provide
   a distributed sink for such queries in order to reduce the load on
   the root and IN-ADDR.ARPA authoritative servers.

   The AS112 project encompasses a loosely coordinated collection of
   independently operated nameservers.  Each nameserver functions as a
   single node in an AS112 anycast cloud [RFC4786], and is configured to
   answer authoritatively for a particular set of nominated zones.

   The AS112 project is named after the Autonomous System Number (ASN)
   that was assigned to it.






















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2.  AS112 DNS Service

2.1.  Zones

   AS112 nameservers answer authoritatively for the following zones,
   corresponding to [RFC1918] private-use netblocks:

   o  10.IN-ADDR.ARPA

   o  16.172.IN-ADDR.ARPA, 17.172.IN-ADDR.ARPA, ..., 31.172.IN-ADDR.ARPA

   o  168.192.IN-ADDR.ARPA

   and the following zone, corresponding to the "link local" netblock
   169.254.0.0/16 listed in [RFC5735]:

   o  254.169.IN-ADDR.ARPA

   To aid identification of AS112 anycast nodes, each node also answers
   authoritatively for the zone HOSTNAME.AS112.NET.

   See Section 3.5 for the recommended contents of all these zones.

   It is possible that other zones corresponding to private-use
   infrastructure will be delegated to AS112 servers in the future.  A
   list of zones for which AS112 servers answer authoritatively is
   maintained at <http://www.as112.net/>.

2.2.  Nameservers

   The zones listed in Section 2.1 are delegated to the two nameservers
   BLACKHOLE-1.IANA.ORG (192.175.48.6) and BLACKHOLE-2.IANA.ORG
   (192.175.48.42).

   Additionally, the server PRISONER.IANA.ORG (192.175.48.1) is listed
   in the MNAME field of the SOA records of the IN-ADDR.ARPA zones
   served by AS112 nameservers.  PRISONER.IANA.ORG receives mainly
   dynamic update queries.

   The addresses of all these nameservers are covered by the single IPv4
   prefix 192.175.48.0/24.










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3.  Installation of a New Node

3.1.  Useful Background Knowledge

   Installation of an AS112 node is relatively straightforward.
   However, experience in the following general areas may prove useful:

   o  inter-domain routing with BGP [RFC4271];

   o  DNS authoritative server operations;

   o  anycast [RFC4786] distribution of DNS services.

3.2.  Topological Location

   AS112 nodes may be located anywhere on the Internet.  For nodes that
   are intended to provide a public service to the Internet community
   (as opposed to private use), it may well be advantageous to choose a
   location that is easily (and cheaply) reachable by multiple
   providers, such as an Internet exchange point.

   AS112 nodes may advertise their service prefix to BGP peers for local
   use (analogous to a conventional peering relationship between two
   providers) or for global use (analogous to a customer relationship
   with one or more providers).

   It is good operational practice to notify the community of users that
   may fall within the reach of a new AS112 node before it is installed.
   At an Internet Exchange, local mailing lists usually exist to
   facilitate such announcements.  For nodes that are intended to be
   globally reachable, coordination with other AS112 operators is highly
   recommended.  See also Section 5.

3.3.  Operating System and Host Considerations

   The use of a UNIX or UNIX-like operating system (e.g.  FreeBSD [1],
   OpenBSD [2], Linux [3]) is recommended for the construction of AS112
   nodes, primarily due to the cumulative experience of using such
   platforms for this purpose.  Examples in this document will assume
   use of such an operating system.

   The chosen platform should include support for either cloned loopback
   interfaces, or the capability to bind multiple addresses to a single
   loopback interface.  The addresses of the nameservers listed in
   Section 2.2 will be configured on these interfaces in order that the
   DNS software can respond to queries properly.

   A host that is configured to act as an AS112 anycast node should be



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   dedicated to that purpose, and should not be used to simultaneously
   provide other services.

   System startup scripts should be arranged such that the various
   AS112-related components start automatically following a system
   reboot.  The order in which interfaces are configured and software
   components started should be arranged such that routing software
   startup follows DNS software startup, and DNS software startup
   follows loopback interface configuration.

   Wrapper scripts or other arrangements should be employed to ensure
   that the anycast service prefix for AS112 is not advertised while
   either the anycast addresses are not configured, or while the DNS
   software is not running.

3.4.  Routing Software

   AS112 nodes signal the availability of AS112 nameservers to the
   Internet using BGP [RFC4271]: each AS112 node is a BGP speaker, and
   announces the prefix 192.175.48.0/24 to the Internet with origin AS
   112 (see also Section 2.2).

   Suitable choices of free software to allow hosts to act as BGP
   speakers include, but are not limited to:

   o  BIRD Internet Routing Daemon [4]

   o  OpenBGPD [5]

   o  The Quagga Routing Suite [6]

   o  GNU Zebra [7]

   The examples in this document are based on Quagga.

   The "bgpd.conf" file is used by Quagga's bgpd daemon, which provides
   BGP protocol support.  The router id in this example is 203.0.113.1;
   the AS112 node peers with external peers 192.0.2.1 and 192.0.2.2.
   Note the local AS number 112, and the origination of the prefix
   192.175.48.0/24.











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   ! bgpd.conf
   !
   hostname as112-bgpd
   password <something>
   enable password <supersomething>
   !
   ! Note that all AS112 nodes use the local Autonomous System
   ! Number 112, and originate the IPv4 prefix 192.175.48.0/24.
   ! All other addresses shown below are illustrative, and
   ! actual numbers will depend on local circumstances.
   !
   router bgp 112
    bgp router-id 203.0.113.1
    network 192.175.48.0
    neighbor 192.0.2.1 remote-as 64496
    neighbor 192.0.2.1 next-hop-self
    neighbor 192.0.2.2 remote-as 64497
    neighbor 192.0.2.2 next-hop-self

   The "zebra.conf" file is required to provide integration between
   protocol daemons (bgpd, in this case) and the kernel.

   ! zebra.conf
   !
   hostname as112
   password <something>
   enable password <supersomething>
   !
   interface lo
   !
   interface eth0
   !

3.5.  DNS Software

   Although the queries received by AS112 nodes are definitively
   misdirected, it is important that they be answered in a manner that
   is accurate and consistent.  For this reason AS112 nodes operate as
   fully-functional and standards-compliant DNS authoritative servers
   [RFC1034], and hence require DNS software.

   Suitable choices of free DNS software for AS112 nodes include, but
   are not limited to:

   o  ISC BIND9 [8]

   o  NLnet Labs' NSD [9]




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   Examples in this document are based on ISC BIND9.

   The following is a sample BIND9 "named.conf" file for a dedicated
   AS112 server.  Note that the nameserver is configured to act as an
   authoritative-only server (i.e. recursion is disabled).  The
   nameserver is also configured to listen on the various AS112 anycast
   nameserver addresses, as well as its local addresses.

   // named.conf

   // global options

   options {
     listen-on {
       127.0.0.1;         // localhost

     // the following address is node-dependent, and should be set to
     // something appropriate for the new AS112 node

       203.0.113.1;       // local address (globally-unique, unicast)

     // the following addresses correspond to AS112 addresses, and
     // are the same for all AS112 nodes

       192.175.48.1;      // prisoner.iana.org (anycast)
       192.175.48.6;      // blackhole-1.iana.org (anycast)
       192.175.48.42;     // blackhole-2.iana.org (anycast)
     };
     directory "/var/named";
     recursion no;        // authoritative-only server
     query-source address *;
   };

   // log queries,  so that when people call us about unexpected
   // answers to queries they didn't realise they had sent, we
   // have something to talk about.  Note that activating this
   // has the potential to create high CPU load and consume
   // enormous amounts of disk space.

   logging {
     channel "querylog" {
       file "/var/log/query.log" versions 2 size 500m;
       print-time yes;
     };
     category queries { querylog; };
   };

   // RFC 1918



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   zone "10.in-addr.arpa" { type master; file "db.empty"; };
   zone "16.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "17.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "18.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "19.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "20.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "21.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "22.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "23.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "24.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "25.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "26.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "27.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "28.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "29.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "30.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "31.172.in-addr.arpa" { type master; file "db.empty"; };
   zone "168.192.in-addr.arpa" { type master; file "db.empty"; };

   // RFC 5735

   zone "254.169.in-addr.arpa" { type master; file "db.empty"; };

   // also answer authoritatively for the HOSTNAME.AS112.NET zone,
   // which contains data of operational relevance

   zone "hostname.as112.net" {
     type master;
     file "db.hostname.as112.net";
   };

   The "db.empty" file follows, below.  This is the source data used to
   populate all the IN-ADDR.ARPA zones listed in Section 2.1.  Note that
   the RNAME specified in the SOA record corresponds to
   hostmaster@root-servers.org, a suitable e-mail address for receiving
   technical queries about these zones.















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   ; db.empty
   ;
   ; Empty zone for AS112 server.
   ;
   $TTL    1W
   @  IN  SOA  prisoner.iana.org. hostmaster.root-servers.org. (
                                  1       ; serial number
                                  1W      ; refresh
                                  1M      ; retry
                                  1W      ; expire
                                  1W )    ; negative caching TTL
   ;
          NS     blackhole-1.iana.org.
          NS     blackhole-2.iana.org.
   ;
   ; There should be no other resource records included in this zone.
   ;
   ; Records that relate to RFC 1918-numbered resources within the
   ; site hosting this AS112 node should not be hosted on this
   ; nameserver.

   The "db.hostname.as112.net" file follows, below.  This zone contains
   various resource records that provide operational data to users for
   troubleshooting or measurement purposes, and should be edited to suit
   local circumstances.  Note that the response to the query
   "HOSTNAME.AS112.NET IN TXT" should fit within a 512 octet DNS/UDP
   datagram: i.e. it should be available over UDP transport without
   requiring EDNS0 support.

   The optional LOC record [RFC1876] included in the zone apex provides
   information about the geospatial location of the node.

   ; db.hostname.as112.net
   ;
   $TTL    1W
   @       SOA     server.example.net. admin.example.net. (
                           1               ; serial number
                           1W              ; refresh
                           1M              ; retry
                           1W              ; expire
                           1W )            ; negative caching TTL
   ;
           NS      blackhole-2.iana.org.
           NS      blackhole-1.iana.org.
   ;
           TXT     "Name of Facility or similar" "City, Country"
           TXT     "See http://www.as112.net/ for more information."
   ;



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           LOC     45 25 0.000 N 75 42 0.000 W 80.00m 1m 10000m 10m

3.6.  Testing a Newly-Installed Node

   The BIND9 tool "dig" can be used to retrieve the TXT resource records
   associated with the domain "HOSTNAME.AS112.NET", directed at one of
   the AS112 anycast nameserver addresses.  Continuing the example from
   above, the response received should indicate the identity of the
   AS112 node that responded to the query.  See Section 3.5 for more
   details about the resource records associated with
   "HOSTNAME.AS112.NET".

       % dig @prisoner.iana.org hostname.as112.net txt +short +norec
       "Name of Facility or similar" "City, Country"
       "See http://www.as112.net/ for more information."
       %

   If the response received indicates a different node is being used,
   then there is probably a routing problem to solve.  If there is no
   response received at all, there might be host or nameserver problem.
   Judicious use of tools such as traceroute, and consultation of BGP
   looking glasses might be useful in troubleshooting.

   Note that an appropriate set of tests for a new server will include
   queries sent from many different places within the expected service
   area of the node, using both UDP and TCP transport, and exercising
   all three AS112 anycast nameserver addresses.
























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4.  Operations

4.1.  Monitoring

   AS112 nodes should be monitored to ensure they are functioning
   correctly, just as with any other production service.  An AS112 node
   that stops answering queries correctly can cause failures and
   timeouts in unexpected places and can lead to failures in dependent
   systems that can be difficult to troubleshoot.

4.2.  Downtime

   An AS112 node that needs to go off-line (e.g. for planned maintenance
   or as part of the diagnosis of some problem) should stop advertising
   the AS112 service prefix to its BGP peers.  This can be done by
   shutting down the routing software on the node altogether or by
   causing the routing system to withdraw the route.

   Withdrawing the service prefix is important in order to avoid
   blackholing query traffic in the event that the DNS software on the
   node is not functioning normally.

4.3.  Statistics and Measurement

   Use of the AS112 node should be measured in order to track long-term
   trends, identify anomalous conditions, and to ensure that the
   configuration of the AS112 node is sufficient to handle the query
   load.

   Examples of free monitoring tools that might be useful to operators
   of AS112 nodes include, but are not limited to:

   o  bindgraph [10]

   o  dnstop [11]

   o  DSC [12]














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5.  Communications

   It is good operational practice to notify the community of users that
   may fall within the reach of a new AS112 node before it is installed.
   At Internet Exchanges, local mailing lists usually exist to
   facilitate such announcements.

   For nodes that are intended to be globally reachable, coordination
   with other AS112 operators is especially recommended.  The mailing
   list <mailto:as112-ops@lists.dns-oarc.net> is operated for this
   purpose.

   Information pertinent to AS112 operations is maintained at
   <http://www.as112.net/>.

   Information about an AS112 node should also be published within the
   DNS, within the "HOSTNAME.AS112.NET" zone.  See Section 3.5 for more
   details.

































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6.  On the Future of AS112 Nodes

   It is recommended practice for the operators of recursive nameservers
   to answer queries for zones served by AS112 nodes locally, such that
   queries never have an opportunity to reach AS112 servers
   [I-D.ietf-dnsop-default-local-zones].  Operational experience with
   AS112 nodes does not currently indicate an observable trend towards
   compliance with those recommendations, however.

   It is expected that some DNS software vendors will include default
   configuration that will implement measures such as those described in
   [I-D.ietf-dnsop-default-local-zones].  If such software is widely
   deployed, it is reasonable to assume that the query load received by
   AS112 nodes will decrease; however, it is safe to assume that the
   query load will not decrease to zero, and consequently that AS112
   nodes will continue to provide a useful service for the foreseeable
   future.

   There may be a requirement in the future for AS112 nodes to answer
   for their current set of zones over IPv6 transport.  Such a
   requirement would necessitate the assignment of a corresponding IPv6
   netblock for use as an anycast service prefix.

   There may be a requirement in the future for AS112 nodes to serve
   additional zones, or to stop serving particular zones that are
   currently served.  Such changes would be widely announced in
   operational forums, and published at <http://www.as112.net/>.
























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7.  IANA Considerations

   The AS112 nameservers are all named under the domain IANA.ORG (see
   Section 2.2).  However, the anycast infrastructure itself is operated
   by a loosely-coordinated, diverse mix of organisations across the
   Internet, and is not an IANA function.

   The autonomous system number 112 and the IPv4 prefix 192.175.48.0/24
   were assigned by ARIN.

   This document makes no request of the IANA.








































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8.  Security Considerations

   Hosts should never normally send queries to AS112 servers; queries
   relating to private-use addresses should be answered locally within a
   site.  Hosts that send queries to AS112 servers may well leak
   information relating to private infrastructure to the public network,
   and this could present a security risk.  This risk is orthogonal to
   the presence or absence of authoritative servers for these zones in
   the public DNS infrastructure, however.

   Queries that are answered by AS112 servers are usually unintentional;
   it follows that the responses from AS112 servers are usually
   unexpected.  Unexpected inbound traffic can trigger intrusion
   detection systems or alerts by firewalls.  Operators of AS112 servers
   should be prepared to be contacted by operators of remote
   infrastructure who believe their security has been violated.  Advice
   to those who mistakenly believe that responses from AS112 nodes
   constitutes an attack on their infrastructure can be found in
   [I-D.ietf-dnsop-as112-under-attack-help-help].

   The deployment of AS112 nodes is very loosely coordinated compared to
   other services distributed using anycast.  The malicious compromise
   of an AS112 node and subversion of the data served by the node is
   hence more difficult to detect due to the lack of central management.
   Since it is conceivable that changing the responses to queries
   received by AS112 nodes might influence the behaviour of the hosts
   sending the queries, such a compromise might be used as an attack
   vector against private infrastructure.

   Operators of AS112 should take appropriate measures to ensure that
   AS112 nodes are appropriately protected from compromise, such as
   would normally be employed for production nameserver or network
   infrastructure.  The guidance provided for root nameservers in
   [RFC2870] may be instructive.

   The zones hosted by AS112 servers are not signed with DNSSEC
   [RFC4033].  Given the distributed and loosely-coordinated structure
   of the AS112 service, the zones concerned could only be signed if the
   private key material used was effectively public, obviating any
   security benefit resulting from the use of those keys.











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9.  Acknowledgements

   The authors wish to acknowledge the assistance of Bill Manning, John
   Brown, Marco D'Itri, Daniele Arena, Stephane Bortzmeyer, Frank
   Habicht, Chris Thompson, Peter Losher, Peter Koch and Alfred Hoenes
   in the preparation of this document.













































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10.  References

10.1.  Normative References

   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
              STD 13, RFC 1034, November 1987.

   [RFC1918]  Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
              E. Lear, "Address Allocation for Private Internets",
              BCP 5, RFC 1918, February 1996.

   [RFC2870]  Bush, R., Karrenberg, D., Kosters, M., and R. Plzak, "Root
              Name Server Operational Requirements", BCP 40, RFC 2870,
              June 2000.

   [RFC4033]  Arends, R., Austein, R., Larson, M., Massey, D., and S.
              Rose, "DNS Security Introduction and Requirements",
              RFC 4033, March 2005.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC4786]  Abley, J. and K. Lindqvist, "Operation of Anycast
              Services", BCP 126, RFC 4786, December 2006.

10.2.  Informative References

   [I-D.ietf-dnsop-as112-under-attack-help-help]
              Abley, J. and W. Maton, "I'm Being Attacked by
              PRISONER.IANA.ORG!",
              draft-ietf-dnsop-as112-under-attack-help-help-04 (work in
              progress), July 2010.

   [I-D.ietf-dnsop-default-local-zones]
              Andrews, M., "Locally-served DNS Zones",
              draft-ietf-dnsop-default-local-zones-14 (work in
              progress), September 2010.

   [RFC1876]  Davis, C., Vixie, P., Goodwin, T., and I. Dickinson, "A
              Means for Expressing Location Information in the Domain
              Name System", RFC 1876, January 1996.

   [RFC5735]  Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
              BCP 153, RFC 5735, January 2010.







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URIs

   [1]   <http://www.freebsd.org/>

   [2]   <http://www.openbsd.org/>

   [3]   <http://www.linuxfoundation.org/>

   [4]   <http://bird.network.cz/>

   [5]   <http://www.openbgpd.org/>

   [6]   <http://www.quagga.net/>

   [7]   <http://www.zebra.org/>

   [8]   <http://www.isc.org/software/BIND/>

   [9]   <http://www.nlnetlabs.nl/nsd/>

   [10]  <http://www.linux.it/~md/software/>

   [11]  <http://dns.measurement-factory.com/tools/dnstop/>

   [12]  <http://dns.measurement-factory.com/tools/dsc/>


























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Appendix A.  History

   Widespread use of the private address blocks listed in [RFC1918]
   followed that document's publication in 1996.

   The idea of off-loading IN-ADDR.ARPA queries relating to [RFC1918]
   addresses from the root nameservers was first proposed by Bill
   Manning and John Brown.

   The use of anycast for distributing authoritative DNS service for
   [RFC1918] IN-ADDR.ARPA zones was subsequently proposed at a private
   meeting of root server operators.

   ARIN provided an IPv4 prefix for the anycast service, and also the
   autonomous system number 112 for use in originating that prefix.
   This assignment gave the project its name.

   In 2002, the first AS112 anycast nodes were deployed.

   The use of anycast nameservers in the AS112 project contributed to
   the operational experience of anycast DNS services, and can be seen
   as a precursor to the anycast distribution of other authoritative DNS
   servers in subsequent years (e.g. various root servers).




























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Appendix B.  Change History

   This section to be removed prior to publication.

   00 Initial draft, circulated as draft-jabley-as112-ops-00 and
      reviewed at the DNSOP working group meeting at IETF 66.

   00 Document adoped by the DNSOP working group and renamed
      accordingly.

   01 Input from reviewers of DNSOP and others, some cosmetic tweaks.

   02 Version bump as request by DNSOP chairs.  Added missing IANA
      Considerations section.  Updated author's addresses.  Make
      http://www.as112.net/ URL consistent.

   03 Fix BLACKHOLE-2.IANA.ORG IP address.

   04 Bump version number.  Refresh references.  Add reference to BIRD.
      Minor wordsmithing.

   05 Updated following review from Peter Koch.

   06 Updated following review from Alfred Hoenes.



























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Authors' Addresses

   Joe Abley
   ICANN
   4676 Admiralty Way, Suite 330
   Marina del Rey, CA  90292
   US

   Phone: +1 519 670 9327
   Email: joe.abley@icann.org


   William F. Maton Sotomayor
   National Research Council of Canada
   1200 Montreal Road
   Ottawa, ON  K1A 0R6
   Canada

   Phone: +1 613 993 0880
   Email: wmaton@ryouko.imsb.nrc.ca































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