diff --git a/doc/draft/draft-ietf-dnsop-default-local-zones-01.txt b/doc/draft/draft-ietf-dnsop-default-local-zones-01.txt new file mode 100644 index 0000000000..652b287aa4 --- /dev/null +++ b/doc/draft/draft-ietf-dnsop-default-local-zones-01.txt @@ -0,0 +1,561 @@ + + + +Network Working Group M. Andrews +Internet-Draft ISC +Intended status: Best Current March 2, 2007 +Practice +Expires: September 3, 2007 + + + Locally-served DNS Zones + draft-ietf-dnsop-default-local-zones-01 + +Status of this Memo + + By submitting this Internet-Draft, each author represents that any + applicable patent or other IPR claims of which he or she is aware + have been or will be disclosed, and any of which he or she becomes + aware will be disclosed, in accordance with Section 6 of BCP 79. + + Internet-Drafts are working documents of the Internet Engineering + Task Force (IETF), its areas, and its working groups. Note that + other groups may also distribute working documents as Internet- + Drafts. + + 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." + + The list of current Internet-Drafts can be accessed at + http://www.ietf.org/ietf/1id-abstracts.txt. + + The list of Internet-Draft Shadow Directories can be accessed at + http://www.ietf.org/shadow.html. + + This Internet-Draft will expire on September 3, 2007. + +Copyright Notice + + Copyright (C) The IETF Trust (2007). + +Abstract + + Practice has shown that there are a number of DNS zones all iterative + resolvers and recursive nameservers should, unless configured + otherwise, automatically serve. RFC 4193 already specifies that this + should occur for D.F.IP6.ARPA. This document extends the practice to + cover the IN-ADDR.ARPA zones for RFC 1918 address space and other + well known zones with similar usage constraints. + + + + +Andrews Expires September 3, 2007 [Page 1] + +Internet-Draft Locally-served DNS Zones March 2007 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.1. Reserved Words . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Effects on sites using RFC 1918 addresses. . . . . . . . . . . 3 + 3. Changes to Iterative Resolver Behaviour. . . . . . . . . . . . 4 + 4. Lists Of Zones Covered . . . . . . . . . . . . . . . . . . . . 5 + 4.1. RFC 1918 Zones . . . . . . . . . . . . . . . . . . . . . . 5 + 4.2. RFC 3330 Zones . . . . . . . . . . . . . . . . . . . . . . 5 + 4.3. Local IPv6 Unicast Addresses . . . . . . . . . . . . . . . 6 + 4.4. IPv6 Locally Assigned Local Addresses . . . . . . . . . . 6 + 4.5. IPv6 Link Local Addresses . . . . . . . . . . . . . . . . 6 + 5. Zones that are Out-Of-Scope . . . . . . . . . . . . . . . . . 6 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7 + 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 + 9.1. Normative References . . . . . . . . . . . . . . . . . . . 8 + 9.2. Informative References . . . . . . . . . . . . . . . . . . 8 + Appendix A. Change History [To Be Removed on Publication] . . . . 9 + A.1. draft-ietf-dnsop-default-local-zones-01.txt . . . . . . . 9 + A.2. draft-ietf-dnsop-default-local-zones-00.txt . . . . . . . 9 + A.3. draft-andrews-full-service-resolvers-03.txt . . . . . . . 9 + A.4. draft-andrews-full-service-resolvers-02.txt . . . . . . . 9 + Appendix B. Proposed Status [To Be Removed on Publication] . . . 9 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 9 + Intellectual Property and Copyright Statements . . . . . . . . . . 10 + + + + + + + + + + + + + + + + + + + + + + + + +Andrews Expires September 3, 2007 [Page 2] + +Internet-Draft Locally-served DNS Zones March 2007 + + +1. Introduction + + Practice has shown that there are a number of DNS [RFC 1034] [RFC + 1035] zones all iterative resolvers and recursive nameservers should, + unless configured otherwise, automatically serve. These zones + include, but are not limited to, the IN-ADDR.ARPA zones for the + address space allocated by [RFC 1918] and the IP6.ARPA zones for + locally assigned local IPv6 addresses, [RFC 4193]. + + This recommendation is made because data has shown that significant + leakage of queries for these name spaces is occurring, despite + instructions to restrict them, and because sacrificial name servers + have been deployed to protect the immediate parent name servers for + these zones from excessive, unintentional, query load [AS112]. There + is every expectation that the query load will continue to increase + unless steps are taken as outlined here. + + Additionally, queries from clients behind badly configured firewalls + that allow outgoing queries but drop responses for these name spaces + also puts a significant load on the root servers. They also cause + operational load for the root server operators as they have to reply + to queries about why the root servers are "attacking" these clients. + Changing the default configuration will address all these issues for + the zones listed below in Section 4. + + [RFC 4193] already recommends that queries for D.F.IP6.ARPA be + handled locally. This document extends the recommendation to cover + the IN-ADDR.ARPA zones for [RFC 1918] and other well known IN- + ADDR.ARPA and IP6.ARPA zones for which queries should not appear on + the public Internet. + + It is hoped that by doing this the number of sacrificial servers + [AS112] will not have to be increased and may in time be reduced. + + It should also help DNS responsiveness for sites which are using [RFC + 1918] addresses but do not follow the last paragraph in section 3 of + [RFC 1918]. + +1.1. Reserved Words + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [RFC 2119]. + + +2. Effects on sites using RFC 1918 addresses. + + For most sites using [RFC 1918] addresses, the changes here will have + + + +Andrews Expires September 3, 2007 [Page 3] + +Internet-Draft Locally-served DNS Zones March 2007 + + + little or no detrimental effect. If the site does not already have + the reverse tree populated the only effect will be that the answers + are generated locally rather than remotely. + + For sites that do have the reverse tree populated, most will either + have a local copy of the zones or will be forwarding the queries to + servers which have local copies of the zone. In either case the + local resolver has a pre-existing configuration for the namespace and + won't add the automatic zone. + + The main impact will be felt at sites that make use of delegation for + reverse lookups for [RFC 1918] addresses and have populated these + zones. Typically, such sites will be fully disconnected from the + Internet and have their own root servers for their own non-Internet + DNS tree. These sites will need to override the default + configuration expressed in this document to allow resolution to + continue. + + +3. Changes to Iterative Resolver Behaviour. + + Unless configured otherwise, an iterative resolver will now return + name errors (RCODE=3) for queries within the lists of zones covered + below, with the obvious exception of queries for the zone name itself + where SOA, NS and "no data" responses will be returned as appropriate + to the query type. One common way to do this is to serve empty (SOA + and NS only) zones. + + A implementation doing this MUST provide a mechanism to disable this + new behaviour, preferably on a zone by zone basis. + + If using empty zones one SHOULD NOT use the same NS and SOA records + as used on the public Internet servers as that will make it harder to + detect leakage to the public Internet servers. This document + recommends that the NS record defaults to the name of the zone and + the SOA MNAME defaults to the name of the only NS RR's target. The + SOA RNAME should default to ".". Implementations SHOULD provide a + mechanism to set these values. No address records need to be + provided for the name server. + + Below is a example of a generic empty zone in master file format. It + will produce a negative cache ttl of 3 hours. + + @ 10800 IN SOA @ . 1 3600 1200 604800 10800 + @ 10800 IN NS @ + + The SOA RR is needed to support negative caching [RFC 2308] of name + error responses and to point clients to the primary master for DNS + + + +Andrews Expires September 3, 2007 [Page 4] + +Internet-Draft Locally-served DNS Zones March 2007 + + + dynamic updates. + + SOA values of particular importance are the MNAME, the SOA RR's TTL + and the negTTL value. Both TTL values SHOULD match. The rest of the + SOA timer values may be chosen arbitrarily since it they are not + intended to control any zone transfer activity. + + The NS RR is needed as some UPDATE clients use NS queries to discover + they zone to be updated. Having no address records for the name + server should abort UPDATE processing in the client + + +4. Lists Of Zones Covered + + The lists below are expected to seed a IANA registry. + +4.1. RFC 1918 Zones + + 10.IN-ADDR.ARPA + 16.172.IN-ADDR.ARPA + 17.172.IN-ADDR.ARPA + 18.172.IN-ADDR.ARPA + 19.172.IN-ADDR.ARPA + 20.172.IN-ADDR.ARPA + 21.172.IN-ADDR.ARPA + 22.172.IN-ADDR.ARPA + 23.172.IN-ADDR.ARPA + 24.172.IN-ADDR.ARPA + 25.172.IN-ADDR.ARPA + 26.172.IN-ADDR.ARPA + 27.172.IN-ADDR.ARPA + 28.172.IN-ADDR.ARPA + 29.172.IN-ADDR.ARPA + 30.172.IN-ADDR.ARPA + 31.172.IN-ADDR.ARPA + 168.192.IN-ADDR.ARPA + +4.2. RFC 3330 Zones + + See [RFC 3330]. + + 0.IN-ADDR.ARPA /* IPv4 "THIS" NETWORK */ + 127.IN-ADDR.ARPA /* IPv4 LOOP-BACK NETWORK */ + 254.169.IN-ADDR.ARPA /* IPv4 LINK LOCAL */ + 2.0.192.IN-ADDR.ARPA /* IPv4 TEST NET */ + 255.255.255.255.IN-ADDR.ARPA /* IPv4 BROADCAST */ + + + + + +Andrews Expires September 3, 2007 [Page 5] + +Internet-Draft Locally-served DNS Zones March 2007 + + +4.3. Local IPv6 Unicast Addresses + + See [RFC 4291], sections 2.4, 2.5.2 and 2.5.3. + + 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP + 6.ARPA + 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP + 6.ARPA + +4.4. IPv6 Locally Assigned Local Addresses + + See [RFC 4193]. + + D.F.IP6.ARPA + +4.5. IPv6 Link Local Addresses + + See [RFC 4291], sections 2.4 and 2.5.6. + + 8.E.F.IP6.ARPA + 9.E.F.IP6.ARPA + A.E.F.IP6.ARPA + B.E.F.IP6.ARPA + + +5. Zones that are Out-Of-Scope + + IPv6 site-local addresses, [RFC 4291] sections 2.4 and 2.57, and IPv6 + Globally Assigned Local [RFC 4193] addresses are not covered here. + It is expected that IPv6 site-local addresses will be self correcting + as IPv6 implementations remove support for site-local addresses. + However, sacrificial servers for C.E.F.IP6.ARPA to F.E.F.IP6.ARPA may + still need to be deployed in the short term if the traffic becomes + excessive. + + For IPv6 Globally Assigned Local addresses [RFC 4291] there has been + no decision made about whether the registries will provide + delegations in this space or not. If they don't, then C.F.IP6.ARPA + will need to be added to the list above. If they do, then registries + will need to take steps to ensure that name servers are provided for + these addresses. + + This document is also ignoring IP6.INT. IP6.INT has been wound up + with only legacy resolvers now generating reverse queries under + IP6.INT. + + This document has also deliberately ignored names immediately under + the root. While there is a subset of queries to the roots which + + + +Andrews Expires September 3, 2007 [Page 6] + +Internet-Draft Locally-served DNS Zones March 2007 + + + could be addressed using the techniques described here (e.g. .local + and IPv4 addresses) there is also a vast amount of traffic that + requires a different strategy (e.g. lookups for unqualied hostnames, + IPv6 addresses). + + +6. IANA Considerations + + This document recommends that IANA establish a registry of zones + which require this default behaviour, the initial contents of which + are in Section 4. More zones are expected to be added, and possibly + deleted from this registry over time. Name server implementors are + encouraged to check this registry and adjust their implementations to + reflect changes therein. + + This registry can be amended through "IETF Consensus" as per [RFC + 2434] or IETF Review in 2434bis. + + IANA should co-ordinate with the RIRs and ICANN to ensure the DNSSEC + deployment in the reverse trees that these zone are delegated in a + unsecure manner as per Security Considerations. + + +7. Security Considerations + + During the initial deployment phase, particularly where [RFC 1918] + addresses are in use, there may be some clients that unexpectedly + receive a name error rather than a PTR record. This may cause some + service disruption until full service resolvers have been re- + configured. + + When DNSSEC is deployed within the IN-ADDR.ARPA and IP6.ARPA + namespaces, the zones listed above will need to be delegated as + insecure delegations. This will allow DNSSEC validation to succeed + for queries in these spaces despite not being answered from the + delegated servers. + + It is recommended that sites actively using these namespaces secure + them using DNSSEC [RFC 4035] by publishing and using DNSSEC trust + anchors. This will protect the clients from accidental leakage of + unsigned answers from the Internet. + + +8. Acknowledgements + + This work was supported by the US National Science Foundation + (research grant SCI-0427144) and DNS-OARC. + + + + +Andrews Expires September 3, 2007 [Page 7] + +Internet-Draft Locally-served DNS Zones March 2007 + + +9. References + +9.1. Normative References + + [RFC 1034] + Mockapetris, P., "DOMAIN NAMES - CONCEPTS AND FACILITIES", + RFC 1034, STD 13, November 1987. + + [RFC 1035] + Mockapetris, P., "DOMAIN NAMES - IMPLEMENTATION AND + SPECIFICATION", RFC 1035, STD 13, November 1987. + + [RFC 1918] + Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G., + and E. Lear, "Address Allocation for Private Internets", + RFC 1918, February 1996. + + [RFC 2119] + Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC 2308] + Andrews, M., "Negative Caching of DNS Queries (DNS + NCACHE)", RFC 2398, March 1998. + + [RFC 2434] + Narten, T. and H. Alvestrand, "Guidelines for Writing an + IANA Considerations Section in RFCs", BCP 26, RFC 2434, + October 1998. + + [RFC 3330] + "Special-Use IPv4 Addresses", RFC 3330, September 2002. + + [RFC 4035] + Arends, R., Austein, R., Larson, M., Massey, D., and S. + Rose, "Protocol Modifications for the DNS Security + Extensions", RFC 4035, March 2005. + + [RFC 4291] + Hinden, R. and S. Deering, "IP Version 6 Addressing + Architecture", RFC 4291, February 2006. + +9.2. Informative References + + [AS112] "AS112 Project", . + + [RFC 4193] + Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast + + + +Andrews Expires September 3, 2007 [Page 8] + +Internet-Draft Locally-served DNS Zones March 2007 + + + Addresses", RFC 4193, October 2005. + + +Appendix A. Change History [To Be Removed on Publication] + +A.1. draft-ietf-dnsop-default-local-zones-01.txt + + Revised impact description. + + Updated to reflect change in IP6.INT status. + +A.2. draft-ietf-dnsop-default-local-zones-00.txt + + Adopted by DNSOP. + + "Author's Note" re-titled "Zones that are Out-Of-Scope" + + Add note that these zone are expected to seed the IANA registry. + + Title changed. + +A.3. draft-andrews-full-service-resolvers-03.txt + + Added "Proposed Status". + +A.4. draft-andrews-full-service-resolvers-02.txt + + Added 0.IN-ADDR.ARPA. + + +Appendix B. Proposed Status [To Be Removed on Publication] + + This Internet-Draft is being submitted for eventual publication as an + RFC with a proposed status of Best Current Practice. + + +Author's Address + + Mark P. Andrews + Internet Systems Consortium + 950 Charter Street + Redwood City, CA 94063 + US + + Email: Mark_Andrews@isc.org + + + + + + +Andrews Expires September 3, 2007 [Page 9] + +Internet-Draft Locally-served DNS Zones March 2007 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2007). + + This document is subject to the rights, licenses and restrictions + contained in BCP 78, and except as set forth therein, the authors + retain all their rights. + + This document and the information contained herein are provided on an + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND + THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS + OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF + THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED + WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + + +Intellectual Property + + The IETF takes no position regarding the validity or scope of any + Intellectual Property Rights or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; nor does it represent that it has + made any independent effort to identify any such rights. 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