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diff --git a/doc/draft/draft-ietf-dnsop-default-local-zones-05.txt b/doc/draft/draft-ietf-dnsop-default-local-zones-05.txt new file mode 100644 index 0000000..230c036 --- /dev/null +++ b/doc/draft/draft-ietf-dnsop-default-local-zones-05.txt @@ -0,0 +1,672 @@ + + + +Network Working Group M. Andrews +Internet-Draft ISC +Intended status: BCP June 5, 2008 +Expires: December 7, 2008 + + + Locally-served DNS Zones + draft-ietf-dnsop-default-local-zones-05 + +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 December 7, 2008. + +Abstract + + Experience has shown that there are a number of DNS zones all + iterative resolvers and recursive nameservers should, unless + configured otherwise, automatically serve. RFC 4193 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 characteristics. + + + + + + + + + +Andrews Expires December 7, 2008 [Page 1] + +Internet-Draft Locally-served DNS Zones June 2008 + + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 1.1. Reserved Words . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Effects on sites using RFC 1918 addresses. . . . . . . . . . . 4 + 3. Changes to Iterative Resolver Behaviour. . . . . . . . . . . . 4 + 4. Lists Of Zones Covered . . . . . . . . . . . . . . . . . . . . 5 + 4.1. RFC 1918 Zones . . . . . . . . . . . . . . . . . . . . . . 5 + 4.2. RFC 3330 Zones . . . . . . . . . . . . . . . . . . . . . . 6 + 4.3. Local IPv6 Unicast Addresses . . . . . . . . . . . . . . . 6 + 4.4. IPv6 Locally Assigned Local Addresses . . . . . . . . . . 6 + 4.5. IPv6 Link Local Addresses . . . . . . . . . . . . . . . . 7 + 5. Zones that are Out-Of-Scope . . . . . . . . . . . . . . . . . 7 + 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 + 7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 + 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 + 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 + 9.1. Normative References . . . . . . . . . . . . . . . . . . . 8 + 9.2. Informative References . . . . . . . . . . . . . . . . . . 10 + Appendix A. Change History [To Be Removed on Publication] . . . . 10 + A.1. draft-ietf-dnsop-default-local-zones-05.txt . . . . . . . 10 + A.2. draft-ietf-dnsop-default-local-zones-04.txt . . . . . . . 10 + A.3. draft-ietf-dnsop-default-local-zones-03.txt . . . . . . . 10 + A.4. draft-ietf-dnsop-default-local-zones-02.txt . . . . . . . 10 + A.5. draft-ietf-dnsop-default-local-zones-01.txt . . . . . . . 11 + A.6. draft-ietf-dnsop-default-local-zones-00.txt . . . . . . . 11 + A.7. draft-andrews-full-service-resolvers-03.txt . . . . . . . 11 + A.8. draft-andrews-full-service-resolvers-02.txt . . . . . . . 11 + Appendix B. Proposed Status [To Be Removed on Publication] . . . 11 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 11 + Intellectual Property and Copyright Statements . . . . . . . . . . 12 + + + + + + + + + + + + + + + + + + + + +Andrews Expires December 7, 2008 [Page 2] + +Internet-Draft Locally-served DNS Zones June 2008 + + +1. Introduction + + Experience has shown that there are a number of DNS [RFC 1034] [RFC + 1035] zones that all iterative resolvers and recursive nameservers + SHOULD, unless intentionally 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 unique 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 it has therefore become + necessary to deploy sacrificial name servers to protect the immediate + parent name servers for these zones from excessive, unintentional, + query load [AS112] [I-D.draft-ietf-dnsop-as112-ops] + [I-D.draft-ietf-dnsop-as112-under-attack-help-help]. 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 for these name spaces but drop the + responses, put a significant load on the root servers (forward but no + reverse zones configured). They also cause operational load for the + root server operators as they have to reply to enquiries about why + the root servers are "attacking" these clients. Changing the default + configuration will address all these issues for the zones listed in + Section 4. + + [RFC 4193] 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. + + This recommendation 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]. + + + + + +Andrews Expires December 7, 2008 [Page 3] + +Internet-Draft Locally-served DNS Zones June 2008 + + +2. Effects on sites using RFC 1918 addresses. + + For most sites using [RFC 1918] addresses, the changes here will have + little or no detrimental effect. If the site does not already have + the reverse tree populated the only effect will be that the name + error responses will be 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. Therefore this + recommendation will not be relevant. + + The most significant impact will be felt at sites that make use of + delegations for [RFC 1918] addresses and have populated these zones. + These sites will need to override the default configuration expressed + in this document to allow resolution to continue. Typically, such + sites will be fully disconnected from the Internet and have their own + root servers for their own non-Internet DNS tree. + + +3. Changes to Iterative Resolver Behaviour. + + Unless configured otherwise, an iterative resolver will now return + authoritatively (aa=1) name errors (RCODE=3) for queries within the + zones in Section 4, 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. + + An implementation of this recommendation MUST provide a mechanism to + disable this new behaviour, and SHOULD allow this decision 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 the origin of the responses and thus any 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 + "nobody.invalid." [RFC 2606]. Implementations SHOULD provide a + mechanism to set these values. No address records need to be + provided for the name server. + + Below is an example of a generic empty zone in master file format. + It will produce a negative cache TTL of 3 hours. + + @ 10800 IN SOA @ nobody.invalid. 1 3600 1200 604800 10800 + @ 10800 IN NS @ + + + +Andrews Expires December 7, 2008 [Page 4] + +Internet-Draft Locally-served DNS Zones June 2008 + + + 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 + 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 they are not + intended to control any zone transfer activity. + + The NS RR is needed as some UPDATE [RFC 2136] clients use NS queries + to discover the zone to be updated. Having no address records for + the name server is expected to abort UPDATE processing in the client. + + +4. Lists Of Zones Covered + + The following subsections are intended to seed the IANA registry as + requested in the IANA Considerations Section. The zone name is the + entity to be registered. + +4.1. RFC 1918 Zones + + The following zones correspond to the IPv4 address space reserved in + [RFC 1918]. + + +----------------------+ + | Zone | + +----------------------+ + | 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 | + +----------------------+ + + + + +Andrews Expires December 7, 2008 [Page 5] + +Internet-Draft Locally-served DNS Zones June 2008 + + +4.2. RFC 3330 Zones + + The following zones correspond to those address ranges from [RFC + 3330] that are not expected to appear as source or destination + addresses on the public Internet and to not have a unique name to + associate with. + + The recommendation to serve an empty zone 127.IN-ADDR.ARPA is not a + attempt to discourage any practice to provide a PTR RR for + 1.0.0.127.IN-ADDR.ARPA locally. In fact, a meaningful reverse + mapping should exist, but the exact setup is out of the scope of this + document. Similar logic applies to the reverse mapping for ::1 + (Section 4.3). The recommendations made here simply assume no other + coverage for these domains exists. + + +------------------------------+------------------------+ + | Zone | Description | + +------------------------------+------------------------+ + | 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 | + +------------------------------+------------------------+ + +4.3. Local IPv6 Unicast Addresses + + The reverse mappings ([RFC 3596], Section 2.5 IP6.ARPA Domain) for + the IPv6 Unspecified (::) and Loopback (::1) addresses ([RFC 4291], + Sections 2.4, 2.5.2 and 2.5.3) are covered by these two zones: + + +-------------------------------------------+ + | Zone | + +-------------------------------------------+ + | 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.IP6.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.IP6.ARPA | + +-------------------------------------------+ + + Note: Line breaks and a escapes '\' have been inserted above for + readability and to adhere to line width constraints. They are not + parts of the zone names. + +4.4. IPv6 Locally Assigned Local Addresses + + Section 4.4 of [RFC 4193] already required special treatment of: + + + + +Andrews Expires December 7, 2008 [Page 6] + +Internet-Draft Locally-served DNS Zones June 2008 + + + +--------------+ + | Zone | + +--------------+ + | D.F.IP6.ARPA | + +--------------+ + +4.5. IPv6 Link Local Addresses + + IPv6 Link-Local Addresses as of [RFC 4291], Section 2.5.6 are covered + by four distinct reverse DNS zones: + + +----------------+ + | Zone | + +----------------+ + | 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 2.5.7, and + IPv6 Non-Locally Assigned Local addresses [RFC 4193] 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 through + F.E.F.IP6.ARPA may still need to be deployed in the short term if the + traffic becomes excessive. + + For IPv6 Non-Locally Assigned Local addresses (L = 0) [RFC 4193], + there has been no decision made about whether the Regional Internet + Registries (RIRs) 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 in + Section 4.4. If they do, then registries will need to take steps to + ensure that name servers are provided for these addresses. + + This document also ignores IP6.INT. IP6.INT has been wound up with + only legacy resolvers now generating reverse queries under IP6.INT + [RFC 4159]. + + This document has also deliberately ignored names immediately under + the root domain. While there is a subset of queries to the root name + servers which could be addressed using the techniques described here + (e.g. .local, .workgroup and IPv4 addresses), there is also a vast + amount of traffic that requires a different strategy (e.g. lookups + for unqualified hostnames, IPv6 addresses). + + + +Andrews Expires December 7, 2008 [Page 7] + +Internet-Draft Locally-served DNS Zones June 2008 + + +6. IANA Considerations + + This document requests that IANA establish a registry of zones which + require this default behaviour. The initial contents of which are in + Section 4. 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]. + + IANA should co-ordinate with the RIRs to ensure that, as DNSSEC is + deployed in the reverse tree, delegations for these zones are made in + the manner described in Section 7. + + +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 their recursive name server(s) have been re- + configured. + + As DNSSEC is deployed within the IN-ADDR.ARPA and IP6.ARPA + namespaces, the zones listed above will need to be delegated as + insecure delegations, or be within insecure zones. 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 import of + unsigned responses from the Internet. + + +8. Acknowledgements + + This work was supported by the US National Science Foundation + (research grant SCI-0427144) and DNS-OARC. + + +9. References + +9.1. Normative References + + [RFC 1034] + Mockapetris, P., "DOMAIN NAMES - CONCEPTS AND FACILITIES", + STD 13, RFC 1034, November 1987. + + + +Andrews Expires December 7, 2008 [Page 8] + +Internet-Draft Locally-served DNS Zones June 2008 + + + [RFC 1035] + Mockapetris, P., "DOMAIN NAMES - IMPLEMENTATION AND + SPECIFICATION", STD 13, RFC 1035, November 1987. + + [RFC 1918] + Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G., + and E. Lear, "Address Allocation for Private Internets", + BCP 5, 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 2136] + Vixie, P., Thomson, A., Rekhter, Y., and J. Bound, + "Dynamic Updates in the Domain Name System (DNS UPDATE)", + RFC 2136, April 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 2606] + Eastlake, D. and A. Panitz, "Reserved Top Level DNS + Names", BCP 32, RFC 2606, June 1999. + + [RFC 3596] + Thomson, S., Huitema, C., Ksinant, V., and M. Souissi, + "DNS Extensions to Support IPv6", RFC 3596, October 2003. + + [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 4159] + Huston, G., "Deprecation of "ip6.int"", BCP 109, RFC 4159, + August 2005. + + [RFC 4193] + Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast + Addresses", RFC 4193, October 2005. + + + + +Andrews Expires December 7, 2008 [Page 9] + +Internet-Draft Locally-served DNS Zones June 2008 + + + [RFC 4291] + Hinden, R. and S. Deering, "IP Version 6 Addressing + Architecture", RFC 4291, February 2006. + +9.2. Informative References + + [AS112] "AS112 Project", <http://www.as112.net/>. + + [I-D.draft-ietf-dnsop-as112-ops] + Abley, J. and W. Maton, "AS112 Nameserver Operations", + draft-ietf-dnsop-as112-ops-00 (work in progress), + February 2007. + + [I-D.draft-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-00 (work in + progress), February 2007. + + [RFC 3330] + "Special-Use IPv4 Addresses", RFC 3330, September 2002. + + +Appendix A. Change History [To Be Removed on Publication] + +A.1. draft-ietf-dnsop-default-local-zones-05.txt + + none, expiry prevention + +A.2. draft-ietf-dnsop-default-local-zones-04.txt + + Centrally Assigned Local addresses -> Non-Locally Assigned Local + address + +A.3. draft-ietf-dnsop-default-local-zones-03.txt + + expanded section 4 descriptions + + Added references [RFC 2136], [RFC 3596], + [I-D.draft-ietf-dnsop-as112-ops] and + [I-D.draft-ietf-dnsop-as112-under-attack-help-help]. + + Revised language. + +A.4. draft-ietf-dnsop-default-local-zones-02.txt + + RNAME now "nobody.invalid." + + + + +Andrews Expires December 7, 2008 [Page 10] + +Internet-Draft Locally-served DNS Zones June 2008 + + + Revised language. + +A.5. draft-ietf-dnsop-default-local-zones-01.txt + + Revised impact description. + + Updated to reflect change in IP6.INT status. + +A.6. 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.7. draft-andrews-full-service-resolvers-03.txt + + Added "Proposed Status". + +A.8. 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 December 7, 2008 [Page 11] + +Internet-Draft Locally-served DNS Zones June 2008 + + +Full Copyright Statement + + Copyright (C) The IETF Trust (2008). + + 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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