| < draft-kh-dnsop-7706bis-00.txt | draft-kh-dnsop-7706bis-01.txt > | |||
|---|---|---|---|---|
| Network Working Group W. Kumari | Network Working Group W. Kumari | |||
| Internet-Draft Google | Internet-Draft Google | |||
| Updates: 7706 (if approved) P. Hoffman | Updates: 7706 (if approved) P. Hoffman | |||
| Intended status: Informational ICANN | Intended status: Informational ICANN | |||
| Expires: September 3, 2018 March 2, 2018 | Expires: December 26, 2018 June 24, 2018 | |||
| Decreasing Access Time to Root Servers by Running One on Loopback | Decreasing Access Time to Root Servers by Running One On The Same Server | |||
| draft-kh-dnsop-7706bis-00 | draft-kh-dnsop-7706bis-01 | |||
| Abstract | Abstract | |||
| Some DNS recursive resolvers have longer-than-desired round-trip | Some DNS recursive resolvers have longer-than-desired round-trip | |||
| times to the closest DNS root server. Some DNS recursive resolver | times to the closest DNS root server. Some DNS recursive resolver | |||
| operators want to prevent snooping of requests sent to DNS root | operators want to prevent snooping of requests sent to DNS root | |||
| servers by third parties. Such resolvers can greatly decrease the | servers by third parties. Such resolvers can greatly decrease the | |||
| round-trip time and prevent observation of requests by running a copy | round-trip time and prevent observation of requests by running a copy | |||
| of the full root zone on a loopback address (such as 127.0.0.1). | of the full root zone on the same server, such as on a loopback | |||
| This document shows how to start and maintain such a copy of the root | address. This document shows how to start and maintain such a copy | |||
| zone that does not pose a threat to other users of the DNS, at the | of the root zone that does not pose a threat to other users of the | |||
| cost of adding some operational fragility for the operator. | DNS, at the cost of adding some operational fragility for the | |||
| operator. | ||||
| This draft will update RFC 7706. See Section 1.1 for a list of | This draft will update RFC 7706. See Section 1.1 for a list of | |||
| topics that will be added in the update. | topics that will be added in the update. | |||
| [ Ed note: Text inside square brackets ([]) is additional background | [ Ed note: Text inside square brackets ([]) is additional background | |||
| information, answers to freqently asked questions, general musings, | information, answers to freqently asked questions, general musings, | |||
| etc. They will be removed before publication.] | etc. They will be removed before publication.] | |||
| [ This document is being collaborated on in Github at: | [ This document is being collaborated on in Github at: | |||
| https://github.com/wkumari/draft-kh-dnsop-7706bis. The most recent | https://github.com/wkumari/draft-kh-dnsop-7706bis. The most recent | |||
| version of the document, open issues, etc should all be available | version of the document, open issues, and so on should all be | |||
| here. The authors (gratefully) accept pull requests ] | available there. The authors gratefully accept pull requests. ] | |||
| Status of This Memo | Status of This Memo | |||
| This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
| provisions of BCP 78 and BCP 79. | provisions of BCP 78 and BCP 79. | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on September 3, 2018. | ||||
| This Internet-Draft will expire on December 26, 2018. | ||||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2018 IETF Trust and the persons identified as the | Copyright (c) 2018 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 1.1. Updates from RFC 7706 . . . . . . . . . . . . . . . . . . 4 | 1.1. Updates from RFC 7706 . . . . . . . . . . . . . . . . . . 4 | |||
| 1.2. Requirements Notation . . . . . . . . . . . . . . . . . . 4 | 1.2. Requirements Notation . . . . . . . . . . . . . . . . . . 5 | |||
| 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 5 | 2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 3. Operation of the Root Zone on the Loopback Address . . . . . 5 | 3. Operation of the Root Zone on the Local Server . . . . . . . 5 | |||
| 4. Using the Root Zone Server on the Loopback Address . . . . . 6 | 4. Using the Root Zone Server on the Same Host . . . . . . . . . 7 | |||
| 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 | 5. Security Considerations . . . . . . . . . . . . . . . . . . . 7 | |||
| 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 | 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 | |||
| 6.1. Normative References . . . . . . . . . . . . . . . . . . 7 | 6.1. Normative References . . . . . . . . . . . . . . . . . . 7 | |||
| 6.2. Informative References . . . . . . . . . . . . . . . . . 7 | 6.2. Informative References . . . . . . . . . . . . . . . . . 8 | |||
| Appendix A. Current Sources of the Root Zone . . . . . . . . . . 7 | Appendix A. Current Sources of the Root Zone . . . . . . . . . . 8 | |||
| Appendix B. Example Configurations of Common Implementations . . 8 | Appendix B. Example Configurations of Common Implementations . . 9 | |||
| B.1. Example Configuration: BIND 9.9 . . . . . . . . . . . . . 8 | B.1. Example Configuration: BIND 9.9 . . . . . . . . . . . . . 9 | |||
| B.2. Example Configuration: Unbound 1.4 and NSD 4 . . . . . . 10 | B.2. Example Configuration: Unbound 1.4 and NSD 4 . . . . . . 10 | |||
| B.3. Example Configuration: Microsoft Windows Server 2012 . . 10 | B.3. Example Configuration: Microsoft Windows Server 2012 . . 11 | |||
| Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 11 | Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 12 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 | |||
| 1. Introduction | 1. Introduction | |||
| DNS recursive resolvers have to provide answers to all queries from | DNS recursive resolvers have to provide answers to all queries from | |||
| their customers, even those for domain names that do not exist. For | their customers, even those for domain names that do not exist. For | |||
| each queried name that has a top-level domain (TLD) that is not in | each queried name that has a top-level domain (TLD) that is not in | |||
| the recursive resolver's cache, the resolver must send a query to a | the recursive resolver's cache, the resolver must send a query to a | |||
| root server to get the information for that TLD, or to find out that | root server to get the information for that TLD, or to find out that | |||
| the TLD does not exist. Typically, the vast majority of queries | the TLD does not exist. Research shows that the vast majority of | |||
| going to the root are for names that do not exist in the root zone, | queries going to the root are for names that do not exist in the root | |||
| and the negative answers are cached for a much shorter period of | zone, partially because the negative answers are cached for a much | |||
| time. A slow path between the recursive resolver and the closest | shorter period of time. A slow path between the recursive resolver | |||
| root server has a negative effect on the resolver's customers. | and the closest root server has a negative effect on the resolver's | |||
| customers. | ||||
| Recursive resolvers currently send queries for all TLDs that are not | Many of the queries from recursive resolvers to root servers get | |||
| in their caches to root servers, even though most of those queries | answers that are referrals to other servers. Malicious third parties | |||
| get answers that are referrals to other servers. Malicious third | might be able to observe that traffic on the network between the | |||
| parties might be able to observe that traffic on the network between | recursive resolver and root servers. | |||
| the recursive resolver and one or more of the DNS roots. | ||||
| This document describes a method for the operator of a recursive | This document describes a method for the operator of a recursive | |||
| resolver to greatly speed these queries and to hide them from | resolver to greatly speed these queries and to hide them from | |||
| outsiders. The basic idea is to create an up-to-date root zone | outsiders. The basic idea is to create an up-to-date root zone | |||
| server on a loopback address on the same host as the recursive | server on the same host as the recursive server, and use that server | |||
| server, and use that server when the recursive resolver looks up root | when the recursive resolver looks up root information. The recursive | |||
| information. The recursive resolver validates all responses from the | resolver validates all responses from the root server on the same | |||
| root server on the loopback address, just as it would all responses | host, just as it would all responses from a remote root server. | |||
| from a remote root server. | ||||
| The primary goals of this design are to provide faster negative | The primary goals of this design are to provide faster negative | |||
| responses to stub resolver queries that contain junk queries, and to | responses to stub resolver queries that contain queries that result | |||
| prevent queries and responses from being visible on the network. | in NXDOMAIN responses, and to prevent queries and responses from | |||
| This design will probably have little effect on getting faster | being visible on the network. This design will probably have little | |||
| positive responses to stub resolver for good queries on TLDs, because | effect on getting faster positive responses to stub resolver for good | |||
| the data for those zones is usually long-lived and already in the | queries on TLDs, because the TTL for most TLDs is usually long-lived | |||
| cache of the recursive resolver; thus, getting faster positive | (on the order of a day or two) and is thus usually already in the | |||
| responses is a non-goal of this design. | cache of the recursive resolver. | |||
| This design explicitly only allows the new root zone server to be run | This design explicitly only allows the new root zone server to be run | |||
| on a loopback address, in order to prevent the server from serving | on the same server as the recursive resolver, in order to prevent the | |||
| authoritative answers to any system other than the recursive | server from serving authoritative answers to any other system. | |||
| resolver. | Specifically, the root server on the local system MUST be configured | |||
| to only answer queries from the resolvers on the same host, and MUST | ||||
| NOT answer queries from any other resolver. | ||||
| It is important to note that the design being described here is not | It is important to note that the design described in this document is | |||
| considered a "best practice". In fact, many people feel that it is | controversial. There is not consensus on whether this is a "best | |||
| an excessively risky practice because it introduces a new operational | practice". In fact, many people feel that it is an excessively risky | |||
| piece to local DNS operations where there was not one before. The | practice because it introduces a new operational piece to local DNS | |||
| advantages listed above do not come free: if this new system does not | operations where there was not one before. The advantages listed | |||
| work correctly, users can get bad data, or the entire recursive | above do not come free: if this new system does not work correctly, | |||
| resolution system might fail in ways that are hard to diagnose. | users can get bad data, or the entire recursive resolution system | |||
| might fail in ways that are hard to diagnose. | ||||
| This design requires the addition of authoritative name server | This design requires the addition of authoritative name server | |||
| software running on the same machine as the recursive resolver. | software running on the same machine as the recursive resolver. | |||
| Thus, recursive resolver software such as BIND will not need to add | Thus, recursive resolver software such as BIND will not need to add | |||
| much new functionality, but recursive resolver software such as | much new functionality, but recursive resolver software such as | |||
| Unbound will need to be able to talk to an authoritative server (such | Unbound will need to be able to talk to an authoritative server (such | |||
| as NSD) running on the same host. | as NSD) running on the same host. However, more recursive resolver | |||
| software might add the capabilities described in this document in th | ||||
| Because of the significant operational risks described in this | future. | |||
| document, distributions of recursive DNS servers MUST NOT include | ||||
| configuration for the design described here. It is acceptable to | ||||
| point to this document, but not to indicate that this configuration | ||||
| is something that should be considered without reading the entire | ||||
| document. | ||||
| A different approach to solving the problems discussed in this | A different approach to solving the problems discussed in this | |||
| document is described in [RFC8198]. | document is described in [RFC8198]. | |||
| 1.1. Updates from RFC 7706 | 1.1. Updates from RFC 7706 | |||
| [ This section will list all the changes from RFC 7706. For this -00 | RFC 7706 explicitly required that the root server instance be run on | |||
| draft, it is the list of changes that we will make in future versions | the loopback interface of the host running the validating resolver. | |||
| of the daft. ] | However, RFC 7706 also had examples of how to set up common software | |||
| that did not use the loopback interface. Thus, this document loosens | ||||
| the restriction on the interface but keeps the requirement that only | ||||
| systems running on that single host be able to query that root server | ||||
| instance. | ||||
| Removed the prohibition on distribution of recursive DNS servers | ||||
| including configurations for this design because some already do, and | ||||
| others have expressed an interest in doing so. | ||||
| Added the idea that a recursive resolver using this design might | ||||
| switch to using the normal (remote) root servers if the local root | ||||
| server fails. | ||||
| [ This section will list all the changes from RFC 7706. For this | ||||
| draft, it is also the list of changes that we will make in future | ||||
| versions of the daft. ] | ||||
| [ Give a clearer comparison of software that allows slaving the root | [ Give a clearer comparison of software that allows slaving the root | |||
| zone in the software (such as BIND) versus resolver software that | zone in the software (such as BIND) versus resolver software that | |||
| requires a local slaved root zone (Unbound). ] | requires a local slaved root zone (Unbound). ] | |||
| [ Add examples of other resolvers such as Knot Resolver and PowerDNS | [ Add examples of other resolvers such as Knot Resolver and PowerDNS | |||
| Recusor, and maybe Windows Server. ] | Recusor, and maybe Windows Server. ] | |||
| [ Add discussion of BIND slaving the root zone in the same view | [ Add discussion of BIND slaving the root zone in the same view | |||
| instead of using different views. ] | instead of using different views. ] | |||
| skipping to change at page 5, line 11 ¶ | skipping to change at page 5, line 21 ¶ | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | |||
| document are to be interpreted as described in [RFC2119]. | document are to be interpreted as described in [RFC2119]. | |||
| 2. Requirements | 2. Requirements | |||
| In order to implement the mechanism described in this document: | In order to implement the mechanism described in this document: | |||
| o The system MUST be able to validate a zone with DNSSEC [RFC4033]. | o The system MUST be able to validate a zone with DNSSEC [RFC4033]. | |||
| o The system MUST have an up-to-date copy of the DNS root key. | o The system MUST have an up-to-date copy of the key used to sign | |||
| the DNS root. | ||||
| o The system MUST be able to retrieve a copy of the entire root zone | o The system MUST be able to retrieve a copy of the entire root zone | |||
| (including all DNSSEC-related records). | (including all DNSSEC-related records). | |||
| o The system MUST be able to run an authoritative server on one of | o The system MUST be able to run an authoritative server for the | |||
| the IPv4 loopback addresses (that is, an address in the range | root zone on the same host. The root server instance MUST only | |||
| 127/8 for IPv4 or ::1 in IPv6). | respond to queries from the same host. One way to assure not | |||
| responding to queries from other hosts is to make the address of | ||||
| the authoritative server one of the IPv4 loopback addresses (that | ||||
| is, an address in the range 127/8 for IPv4 or ::1 in IPv6). | ||||
| A corollary of the above list is that authoritative data in the root | A corollary of the above list is that authoritative data in the root | |||
| zone used on the local authoritative server MUST be identical to the | zone used on the local authoritative server MUST be identical to the | |||
| same data in the root zone for the DNS. It is possible to change the | same data in the root zone for the DNS. It is possible to change the | |||
| unsigned data (the glue records) in the copy of the root zone, but | unsigned data (the glue records) in the copy of the root zone, but | |||
| such changes could cause problems for the recursive server that | such changes could cause problems for the recursive server that | |||
| accesses the local root zone, and therefore any changes to the glue | accesses the local root zone, and therefore any changes to the glue | |||
| records SHOULD NOT be made. | records SHOULD NOT be made. | |||
| 3. Operation of the Root Zone on the Loopback Address | 3. Operation of the Root Zone on the Local Server | |||
| The operation of an authoritative server for the root in the system | The operation of an authoritative server for the root in the system | |||
| described here can be done separately from the operation of the | described here can be done separately from the operation of the | |||
| recursive resolver. | recursive resolver, or it might be part of the configuration of the | |||
| recursive resolver system. | ||||
| The steps to set up the root zone are: | The steps to set up the root zone are: | |||
| 1. Retrieve a copy of the root zone. (See Appendix A for some | 1. Retrieve a copy of the root zone. (See Appendix A for some | |||
| current locations of sources.) | current locations of sources.) | |||
| 2. Start the authoritative server with the root zone on a loopback | 2. Start the authoritative server with the root zone on an address | |||
| address that is not in use. For IPv4, this would typically be | on the host that is not in use. For IPv4, this could be | |||
| 127.0.0.1, but if that address is in use, any address in 127/8 is | 127.0.0.1, but if that address is in use, any address in 127/8 is | |||
| acceptable. For IPv6, this would be ::1. | acceptable. For IPv6, this would be ::1. It can also be a | |||
| publicly-visible address on the host, but only if the | ||||
| authoritative server software allows restricting the addresses | ||||
| that can access the authoritative server, and the software is | ||||
| configured to only allow access from addresses on this single | ||||
| host. | ||||
| The contents of the root zone MUST be refreshed using the timers from | The contents of the root zone MUST be refreshed using the timers from | |||
| the SOA record in the root zone, as described in [RFC1035]. This | the SOA record in the root zone, as described in [RFC1035]. This | |||
| inherently means that the contents of the local root zone will likely | inherently means that the contents of the local root zone will likely | |||
| be a little behind those of the global root servers because those | be a little behind those of the global root servers because those | |||
| servers are updated when triggered by NOTIFY messages. If the | servers are updated when triggered by NOTIFY messages. | |||
| contents of the zone cannot be refreshed before the expire time, the | ||||
| server MUST return a SERVFAIL error response for all queries until | If the contents of the root zone cannot be refreshed before the | |||
| the zone can be successfully be set up again. | expire time in the SOA, the local root server MUST return a SERVFAIL | |||
| error response for all queries sent to it until the zone can be | ||||
| successfully be set up again. Because this would cause a recursive | ||||
| resolver on the same host that is relying on this root server to also | ||||
| fail, a resolver might be configured to immediatly switch to using | ||||
| other (non-local) root servers if the resolver receives a SERVFAIL | ||||
| response from a local root server. | ||||
| In the event that refreshing the contents of the root zone fails, the | In the event that refreshing the contents of the root zone fails, the | |||
| results can be disastrous. For example, sometimes all the NS records | results can be disastrous. For example, sometimes all the NS records | |||
| for a TLD are changed in a short period of time (such as 2 days); if | for a TLD are changed in a short period of time (such as 2 days); if | |||
| the refreshing of the local root zone is broken during that time, the | the refreshing of the local root zone is broken during that time, the | |||
| recursive resolver will have bad data for the entire TLD zone. | recursive resolver will have bad data for the entire TLD zone. | |||
| An administrator using the procedure in this document SHOULD have an | An administrator using the procedure in this document SHOULD have an | |||
| automated method to check that the contents of the local root zone | automated method to check that the contents of the local root zone | |||
| are being refreshed. One way to do this is to have a separate | are being refreshed; this might be part of the resolver software. | |||
| process that periodically checks the SOA of the root zone from the | One way to do this is to have a separate process that periodically | |||
| local root zone and makes sure that it is changing. At the time that | checks the SOA of the root zone from the local root zone and makes | |||
| this document is published, the SOA for the root zone is the digital | sure that it is changing. At the time that this document is | |||
| representation of the current date with a two-digit counter appended, | published, the SOA for the root zone is the digital representation of | |||
| and the SOA is changed every day even if the contents of the root | the current date with a two-digit counter appended, and the SOA is | |||
| zone are unchanged. For example, the SOA of the root zone on January | changed every day even if the contents of the root zone are | |||
| 2, 2015 was 2015010201. A process can use this fact to create a | unchanged. For example, the SOA of the root zone on January 2, 2018 | |||
| check for the contents of the local root zone (using a program not | was 2018010201. A process can use this fact to create a check for | |||
| specified in this document). | the contents of the local root zone (using a program not specified in | |||
| this document). | ||||
| 4. Using the Root Zone Server on the Loopback Address | 4. Using the Root Zone Server on the Same Host | |||
| A recursive resolver that wants to use a root zone server operating | A recursive resolver that wants to use a root zone server operating | |||
| as described in Section 3 simply specifies the local address as the | as described in Section 3 simply specifies the local address as the | |||
| place to look when it is looking for information from the root. All | place to look when it is looking for information from the root. All | |||
| responses from the root server must be validated using DNSSEC. | responses from the root server MUST be validated using DNSSEC. | |||
| Note that using this configuration will cause the recursive resolver | Note that using this simplistic configuration will cause the | |||
| to fail if the local root zone server fails. See Appendix B for more | recursive resolver to fail if the local root zone server fails. A | |||
| discussion of this for specific software. | more robust configuration would cause the resolver to start using the | |||
| normal remote root servers when the local root server fails (such as | ||||
| if it does not respond or gives SERVFAIL responses). | ||||
| See Appendix B for more discussion of this for specific software. | ||||
| To test the proper operation of the recursive resolver with the local | To test the proper operation of the recursive resolver with the local | |||
| root server, use a DNS client to send a query for the SOA of the root | root server, use a DNS client to send a query for the SOA of the root | |||
| to the recursive server. Make sure the response that comes back has | to the recursive server. Make sure the response that comes back has | |||
| the AA bit in the message header set to 0. | the AA bit in the message header set to 0. | |||
| 5. Security Considerations | 5. Security Considerations | |||
| A system that does not follow the DNSSEC-related requirements given | A system that does not follow the DNSSEC-related requirements given | |||
| in Section 2 can be fooled into giving bad responses in the same way | in Section 2 can be fooled into giving bad responses in the same way | |||
| as any recursive resolver that does not do DNSSEC validation on | as any recursive resolver that does not do DNSSEC validation on | |||
| responses from a remote root server. Anyone deploying the method | responses from a remote root server. Anyone deploying the method | |||
| described in this document should be familiar with the operational | described in this document should be familiar with the operational | |||
| benefits and costs of deploying DNSSEC [RFC4033]. | benefits and costs of deploying DNSSEC [RFC4033]. | |||
| As stated in Section 1, this design explicitly only allows the new | As stated in Section 1, this design explicitly only allows the new | |||
| root zone server to be run on a loopback address, in order to prevent | root zone server to be run on the same host, answering queries only | |||
| the server from serving authoritative answers to any system other | from resolvers on that host, in order to prevent the server from | |||
| than the recursive resolver. This has the security property of | serving authoritative answers to any system other than the recursive | |||
| limiting damage to any other system that might try to rely on an | resolver. This has the security property of limiting damage to any | |||
| altered copy of the root. | other system that might try to rely on an altered copy of the root. | |||
| 6. References | 6. References | |||
| 6.1. Normative References | 6.1. Normative References | |||
| [RFC1035] Mockapetris, P., "Domain names - implementation and | [RFC1035] Mockapetris, P., "Domain names - implementation and | |||
| specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, | specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, | |||
| November 1987, <https://www.rfc-editor.org/info/rfc1035>. | November 1987, <https://www.rfc-editor.org/info/rfc1035>. | |||
| [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
| skipping to change at page 8, line 32 ¶ | skipping to change at page 9, line 18 ¶ | |||
| recursive server software that is believed to correctly implement the | recursive server software that is believed to correctly implement the | |||
| requirements given in this document. | requirements given in this document. | |||
| The IPv4 and IPv6 addresses in this section were checked recently by | The IPv4 and IPv6 addresses in this section were checked recently by | |||
| testing for AXFR over TCP from each address for the known single- | testing for AXFR over TCP from each address for the known single- | |||
| letter names in the root-servers.net zone. | letter names in the root-servers.net zone. | |||
| The examples here use a loopback address of 127.12.12.12, but typical | The examples here use a loopback address of 127.12.12.12, but typical | |||
| installations will use 127.0.0.1. The different address is used in | installations will use 127.0.0.1. The different address is used in | |||
| order to emphasize that the root server does not need to be on the | order to emphasize that the root server does not need to be on the | |||
| device at "localhost". | device at the name "localhost" which is often locally served as | |||
| 127.0.0.1. | ||||
| B.1. Example Configuration: BIND 9.9 | B.1. Example Configuration: BIND 9.9 | |||
| BIND acts both as a recursive resolver and an authoritative server. | BIND acts both as a recursive resolver and an authoritative server. | |||
| Because of this, there is "fate-sharing" between the two servers in | Because of this, there is "fate-sharing" between the two servers in | |||
| the following configuration. That is, if the root server dies, it is | the following configuration. That is, if the root server dies, it is | |||
| likely that all of BIND is dead. | likely that all of BIND is dead. | |||
| Using this configuration, queries for information in the root zone | Using this configuration, queries for information in the root zone | |||
| are returned with the AA bit not set. | are returned with the AA bit not set. | |||
| skipping to change at page 11, line 48 ¶ | skipping to change at page 12, line 35 ¶ | |||
| the loopback address is not a new concept, and that we have chatted | the loopback address is not a new concept, and that we have chatted | |||
| with many people about that idea over time. For example, Bill | with many people about that idea over time. For example, Bill | |||
| Manning described a similar solution but to a very different problem | Manning described a similar solution but to a very different problem | |||
| (intermittent connectivity, instead of constant but slow | (intermittent connectivity, instead of constant but slow | |||
| connectivity) in his doctoral dissertation in 2013 [Manning2013]. | connectivity) in his doctoral dissertation in 2013 [Manning2013]. | |||
| Evan Hunt contributed greatly to the logic in the requirements. | Evan Hunt contributed greatly to the logic in the requirements. | |||
| Other significant contributors include Wouter Wijngaards, Tony Hain, | Other significant contributors include Wouter Wijngaards, Tony Hain, | |||
| Doug Barton, Greg Lindsay, and Akira Kato. The authors also received | Doug Barton, Greg Lindsay, and Akira Kato. The authors also received | |||
| many offline comments about making the document clear that this is | many offline comments about making the document clear that this is | |||
| just a description of a way to operate a root zone on localhost, and | just a description of a way to operate a root zone on the same host, | |||
| not a recommendation to do so. | and not a recommendation to do so. | |||
| Authors' Addresses | Authors' Addresses | |||
| Warren Kumari | Warren Kumari | |||
| Email: Warren@kumari.net | Email: Warren@kumari.net | |||
| Paul Hoffman | Paul Hoffman | |||
| ICANN | ICANN | |||
| End of changes. 31 change blocks. | ||||
| 99 lines changed or deleted | 136 lines changed or added | |||
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