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Versions: 00 01 02 03

Network Working Group                                          W. Kumari
Internet-Draft                                                    Google
Updates: 6304 (if approved)                                 W. Sotomayor
Intended status: BCP                                            NRC-CNRC
Expires: December 1, 2012                                       J. Abley
                                                                   ICANN
                                                            May 30, 2012


                        Omniscient AS112 Servers
                draft-wkumari-dnsop-omniscient-as112-00

Abstract

   The AS112 Project loosely coordinates Domain Name System (DNS)
   servers to which DNS zones corresponding to private use addresses are
   delegated.  Queries for names within those zones have no useful
   responses in a global context.  The purpose of the project is to
   reduce the load of such junk queries on the authoritative name
   servers that would otherwise receive them, directing the load instead
   to name servers operated within the AS112 project.

   Adding and dropping zones from the AS112 servers is difficult, due to
   the loosely-coordinated nature of the project.  This document
   proposes a mechanism by which AS112 name servers could answer
   authoritatively for all possible zones, reducing the add/drop problem
   to one of delegation within the DNS without operational impact on the
   servers themselves.

   This document updates RFC 6304.

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 December 1, 2012.




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Copyright Notice

   Copyright (c) 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Protocol Considerations  . . . . . . . . . . . . . . . . . . .  4
   4.  Operational Considerations . . . . . . . . . . . . . . . . . .  4
   5.  Addressing Considerations  . . . . . . . . . . . . . . . . . .  5
   6.  Updates to RFC 6304  . . . . . . . . . . . . . . . . . . . . .  5
     6.1.  Changes to Section 3.4, Routing Software . . . . . . . . .  5
     6.2.  Changes to Section 3.5, DNS Software . . . . . . . . . . .  7
     6.3.  Changes to Section 3.6, Testing a Newly Installed Node . .  9
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 10
   9.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 10
     10.2. Informative References . . . . . . . . . . . . . . . . . . 10
   Appendix A.  Document Notes  . . . . . . . . . . . . . . . . . . . 11
     A.1.  Venue  . . . . . . . . . . . . . . . . . . . . . . . . . . 11
     A.2.  Textual Substitutions  . . . . . . . . . . . . . . . . . . 11
     A.3.  Open Questions . . . . . . . . . . . . . . . . . . . . . . 11
     A.4.  Change History . . . . . . . . . . . . . . . . . . . . . . 11
       A.4.1.  draft-wkumari-dnsop-omniscient-as112-00  . . . . . . . 11
       A.4.2.  draft-wkumari-omniscient-as112-00  . . . . . . . . . . 12
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12










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1.  Introduction

   The AS112 Project loosely coordinates Domain Name System (DNS)
   servers [RFC1034] to which DNS zones corresponding to private use
   addresses are delegated.  Queries for names within those zones have
   no useful responses in a global context.  The purpose of the project
   is to reduce the load of such junk queries on the authoritative name
   servers that would otherwise receive them, directing the load instead
   to name servers operated within the AS112 project.

   To date, AS112 nameservers have been used exclusively for names
   corresponding to the reverse mapping for private-use IPv4 addresses.
   A description of current advice for AS112 operators, including
   motivations and guidance for technical deployment and operations can
   be found in [RFC6304].

   Other DNS domains have analogously local significance.  Examples
   corresponding to the reverse-mapping of special-use IPv4 and IPv6
   addresses can be found in [RFC6303].

   It is to be expected that new domains will be identified from time to
   time that fit the use pattern for which delegation to AS112 servers
   might be desirable.  There is currently no mechanism by which
   particular zones can be reliably added to or dropped from AS112
   servers, however.  This is principally a consequence of the loosely-
   coordinated nature of the project, coupled with a desire to avoid
   lame delegations which might have unforseen operational consequences.

   This document proposes a mechanism by which AS112 servers could
   provide consistent, reliable negative responses for all DNS queries,
   eliminating the operational requirement to add or drop particular
   zones from all AS112 servers.


2.  Terminology

   An "Existing AS112 Server" is a DNS name server configured according
   to the guidance provided in [RFC6304] and listening on the IPv4
   addresses 192.175.48.1 (PRISONER.IANA.ORG), 192.175.48.6 (BLACKHOLE-
   1.IANA.ORG) and 192.175.48.42 (BLACKHOLE-2.IANA.ORG).

   An "Omniscient AS112 Server" is a DNS nameserver configured according
   to the guidance provided in [RFC6304], as extended by this document.
   Such servers listen on the same addresses as Existing AS112 Servers,
   but also additional addresses as described in Section 5.

   Where discussions apply equally to Existing AS112 Servers and
   Omniscient AS112 Servers, the unqualified phrase "AS112 Server" is



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   used.

   An "AS112 Zone" is a DNS zone which has been delegated to an AS112
   Server.

   An "Existing AS112 Zone" is an AS112 Zone which has been delegated to
   an existing AS112 Server.


3.  Protocol Considerations

   An AS112 Server responds with an authoritative (AA=1) name error
   (NXDOMAIN, RCODE=3) for any query request whose (QNAME, QCLASS) falls
   within an AS112 Zone [RFC1035].

   AS112 Servers do not respond to zone transfer requests (QTYPE=252).

   The name error (NXDOMAIN) response from an Omnisicient AS112 Server
   differs from that sent by an Existing AS112 Server in that the
   closest enclosing SOA returned has a different owner name.  Existing
   AS112 Servers return an authority-section SOA with an owner name
   corresponding to the apex of the AS112 Zone concerned; Omniscient
   AS112 Servers return an SOA with an owner name of ".".  This
   difference has not been shown to cause any practical change in
   behaviour in commonly-deployed DNS resolver software.


4.  Operational Considerations

   Existing AS112 Servers address the protocol considerations described
   in Section 3 by serving each Existing AS112 Zone explicitly.  In each
   case the zone contents are identical, containing only required apex
   SOA and NS records.  Adding or dropping a delegation for an Existing
   AS112 Zone requires coordination amongst all deployed Existing AS112
   Server operators in order to add or drop the zone.

   There is no practical expectation that AS112 Server operators
   coordinate the configuration of their infrastructure or even make
   their existence known in any systematic way.  Delegation of new zones
   to Existing AS112 Servers is hence problematic; there is an
   expectation that such delegations would be lame for a significant
   client population.  Since the predictable behaviour of AS112 Servers
   from clients is desirable, and it is possible that significant
   variation would have operational consequences, no new zones should be
   delegated to existing AS112 Servers.

   Omniscient AS112 Servers serve an unsigned root zone, containing only
   required apex SOA and NS records.  Adding or dropping a delegation



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   for an AS112 Zone requires imposes no operational requirements on
   Omniscient AS112 Server operators.

   Delegation of new AS112 Zones should only be made to Omniscient AS112
   Servers.  The desire to delegate new AS112 Zones therefore imposes a
   requirement on Omnisicient AS112 Servers to listen on addresses which
   are different to those used by Existing AS112 Servers.  Addressing is
   discussed in Section 5.

   By ensuring that Omnisicient AS112 Servers listen on Existing AS112
   Servers' addresses as well as the new addresses specified in
   Section 5 a smooth migration is possible, allowing Existing AS112
   Servers to be reconfigured as Omnisicient AS112 Servers.  Omnisicient
   AS112 Servers are therefore a superset of AS112 Servers.


5.  Addressing Considerations

   Omniscient AS112 Servers listen on the following addresses:

   o  IPv4-TBA1 (A.AS112.NET)
   o  IPv6-TBA1 (A.AS112.NET)
   o  IPv4-TBA2 (B.AS112.NET)
   o  IPv6-TBA2 (B.AS112.NET)
   o  IPv4-TBA3 (C.AS112.NET)
   o  IPv6-TBA3 (C.AS112.NET)

   Pv4-TBA1, IPv4-TBA2 and IPv4-TBA3 are covered by a single IPv4
   prefix, IPv4-PREFIX-TBA.  Similarly, IPv6-TBA1, IPv6-TBA2 and IPv6-
   TBA3 are covered by a single IPv6 prefix, IPv6-PREFIX-TBA.

   The addresses specified for Omnisicient AS112 Servers are
   deliberately different from those assigned to Existing AS112 Servers
   for reasons discussed in Section 4.


6.  Updates to RFC 6304

6.1.  Changes to Section 3.4, Routing Software

   Omnisicient AS112 Nodes with IPv4 connectivity should originate the
   IPv4 service prefix associated with Existing AS112 Nodes,
   192.175.48.0/24, and also the IPv4 service prefix associated with
   Omniscient AS112 Nodes, IPv4-PREFIX.

   Omniscient AS112 Nodes with IPv6 connectivity should originate the
   IPv6 service prefix IPv6-PREFIX-TBA.




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   Applying this direction to the "bgpd.conf" file included as an
   example in this section results in the configuration shown in
   Figure 1.

      ! bgpd.conf
      !
      hostname as112-bgpd
      password <something>
      enable password <supersomething>
      !
      ! Note that all AS112 nodes use the local Autonomous System
      ! Number 112, and originate IPv4 and IPv6 prefixes (where IPv4
      ! and IPv6 connectivity is available) as follows:
      !
      !   IPv4:  192.175.48.0/24
      !          IPv4-PREFIX-TBA
      !
      !   IPv6:  IPv6-PREFIX-TBA
      !
      ! 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
       !
       address-family ipv4
         network 192.175.48.0
         neighbor 192.0.2.1 remote-as 64496
         neighbor 192.0.2.1 next-hop-self
         neighbor 192.0.2.1 prefix-list AS112-v4 out
         neighbor 192.0.2.1 filter-list 1 out
         neighbor 192.0.2.2 remote-as 64497
         neighbor 192.0.2.2 next-hop-self
         neighbor 192.0.2.2 prefix-list AS112-v4 out
         neighbor 192.0.2.2 filter-list 1 out
         network 192.175.48.0/24
         network IPv4-PREFIX-TBA
       !
       address-family ipv6 unicast
         neighbor 2001:db8::1 remote-as 64496
         neighbor 2001:db8::1 next-hop-self
         neighbor 2001:db8::1 prefix-list AS112-v6 out
         neighbor 2001:db8::1 filter-list 1 out
         neighbor 2001:db8::2 remote-as 64497
         neighbor 2001:db8::2 next-hop-self
         neighbor 2001:db8::2 prefix-list AS112-v6 out
         neighbor 2001:db8::2 filter-list 1 out
         network IPv6-PREFIX-TBA



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      !
      ip prefix-list AS112-v4 permit 192.175.48.0/24
      ip prefix-list AS112-v4 permit IPv4-PREFIX-TBA
      !
      ipv6 prefix-list AS112-v6 permit IPv6-PREFIX-TBA
      !
      ip as-path access-list 1 permit ^$

                                 Figure 1

6.2.  Changes to Section 3.5, DNS Software

   Omniscient AS112 Servers with IPv4 connectivity should include DNS
   software configured to listen on the addresses IPv4-TBA1, IPv4-TBA2
   and IPv4-TBA3 in addition to the addresses used by Existing AS112
   Servers.

   Omniscient AS112 Servers with IPv6 connectivity should include DNS
   software configured to listen on the addresses IPv6-TBA1, IPv6-TBA2
   and IPv6-TBA3.

   Omniscient AS112 Servers serve an empty, unsigned root zone instead
   of explicitly serving the zones specified in [RFC6304].

   Applying this direction to the "named.conf" file included as an
   example in this section results in the configuration fragment shown
   in Figure 2.

   options {
     // The following configuration stanza is for Omniscient AS112
     // Servers with IPv4 connectivity

     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 Existing AS112 Server
     // addresses

       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)

     // the following addresses are required by Omniscient AS112 Servers



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       IPv4-TBA1;         // A.AS112.NET
       IPv4-TBA2;         // B.AS112.NET
       IPv4-TBA3;         // C.AS112.NET
     };

     // The following configuration stanza is for Omniscient AS112
     // Servers with IPv6 connectivity

     listen-on-v6 {
       ::1;               // localhost

       IPv6-TBA1;         // A.AS112.NET
       IPv6-TBA2;         // B.AS112.NET
       IPv6-TBA3;         // C.AS112.NET
     };

     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; };
   };

   // Substantially empty root zone (replaces explicit zone
   // configuration specified in RFC 6304 for Existing AS112 Servers)

   zone "." {
     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;



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     file "db.hostname.as112.net";

   // No other zones should be hosted on this name server.
   };

                                 Figure 2

   The "db.empty" file is updated to include references to nameservers
   used by Omniscient AS112 Servers, as shown in Figure 3.

      ; db.empty
      ;
      ; Empty zone for AS112 server.
      ;
      $TTL    1W
      @  IN  SOA  A.AS112.NET. hostmaster.root-servers.org. (
                                     1       ; serial number
                                     1W      ; refresh
                                     1M      ; retry
                                     1W      ; expire
                                     1W )    ; negative caching TTL
      ;
             NS     B.AS112.NET.
             NS     C.AS112.NET.
      ;
      ; There should be no other resource records included in this zone.
      ;

                                 Figure 3

6.3.  Changes to Section 3.6, Testing a Newly Installed Node

   Testing should include all configured service addresses for an
   Omniscient AS112 Server (IPv4 or IPv6 or both, as appropriate).  Note
   that the IPv4 service addresses include those described in [RFC6304]
   for Existing AS112 Servers.


7.  IANA Considerations

   This document describes infrastructure which could be used in the
   future to direct the IANA to delegate or redelegate infrastructure
   zones under its administrative control.

   However, this document makes no request of the IANA.






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8.  Security Considerations

   The contents of the Security Considerations section of [RFC6304]
   should be reviewed, since that discussion is pertinent to the
   operation of Omniscient AS112 Servers as well as Existing AS112
   Servers.

   The deployment of Omniscient AS112 Servers enables new delegations to
   AS112 Servers.

   Queries received by an AS112 Server might reveal operational data for
   which there is an expectation of privacy.  For example, leaked
   queries for an organisation's internal DNS names which are sent to an
   AS112 Server might reveal the existence of those names to the AS112
   Server operator.  The delegation of new zones to AS112 Servers has
   the potential to increase opportunities for such unintentional
   information leakage.

   The delegation of new zones to AS112 Servers has the potential to
   increase the traffic received by those servers.  AS112 Server
   operators are encouraged to monitor traffic levels, and to take
   appropriate steps if traffic levels threaten the stability of their
   networks.


9.  Acknowledgements

   The authors thank and acknowledge the contributions of Dr Paul Vixie,
   Shane Kerr and Bill Manning in the preparation of this document.


10.  References

10.1.  Normative References

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

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

   [RFC6304]  Abley, J. and W. Maton, "AS112 Nameserver Operations",
              RFC 6304, July 2011.

10.2.  Informative References

   [RFC6303]  Andrews, M., "Locally Served DNS Zones", BCP 163,
              RFC 6303, July 2011.



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Appendix A.  Document Notes

   This section (and sub-sections) contain information useful for
   development and review of this document, and should be removed prior
   to publication.

A.1.  Venue

   This document is an individual submission, and is not the product of
   an IETF working group.  However, a suitable venue for discussion is
   the dnsop working group mailing list.

A.2.  Textual Substitutions

   The strings "IPv4-TBA1", "IPv4-TBA2" and "IPv4-TBA3" should be
   replaced in this document should be replaced with IPv4 addresses
   assigned for the purpose described.  The covering IPv4 prefix for all
   three addresses should replace the string "IPv4-PREFIX-TBA".

   Similarly, the strings "IPv6-TBA1", "IPv6-TBA2", "IPv6-TBA3" and
   "IPv6-PREFIX-TBA" should be substituted in the text with assigned
   production values.

A.3.  Open Questions

   1.  Where to get IPv4 and IPv6 assignments from?  There has already
       been an assignment to DNS-OARC by ARIN for v6 service for AS112
       servers.

A.4.  Change History

A.4.1.  draft-wkumari-dnsop-omniscient-as112-00

   Document title changed to include the dnsop keyword, so that IETF
   document automation can send courtesy notifications of document
   actions to the dnsop working group.

   Abstract and introduction expanded.

   RFC2119 requirements notation removed, since this is an informational
   document and any normative language would be toothless.

   Discussion broken out into Protocol Considerations, Operational
   Considerations and Addressing Considerations.

   Detailed updates to [RFC6304] added.





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A.4.2.  draft-wkumari-omniscient-as112-00

   Initial draft, circulated privately, not submitted.


Authors' Addresses

   Warren Kumari
   Google
   1600 Ampitheatre Parkway
   Mountain View, CA  94043
   USA

   Email: warren@kumari.net


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

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


   Joe Abley
   ICANN
   12025 Waterfront Drive, Suite 300
   Los Angeles, CA  90094-2536
   USA

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

















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