Internet Engineering Task Force (IETF) M. Andrews

Request for Comments: 7793 ISC

BCP: 163 May 2016

Category: Best Current Practice

ISSN: 2070-1721

Adding 100.64.0.0/10 Prefixes to the

IPv4 Locally-Served DNS Zones Registry

Abstract

RFC 6598 specifies that "Reverse DNS queries for Shared Address Space

addresses [100.64.0.0/10] MUST NOT be forwarded to the global DNS

infrastructure."

This document formally directs IANA to add the associated zones to

the "IPv4 Locally-Served DNS Zones Registry" to prevent such queries

from accidentally leaking to the global DNS infrastructure.

Status of This Memo

This memo documents an Internet Best Current Practice.

This document is a product of the Internet Engineering Task Force

(IETF). It represents the consensus of the IETF community. It has

received public review and has been approved for publication by the

Internet Engineering Steering Group (IESG). Further information on

BCPs is available in Section 2 of RFC 5741.

Information about the current status of this document, any errata,

and how to provide feedback on it may be obtained at

http://www.rfc-editor.org/info/rfc7793.

Copyright Notice

Copyright (c) 2016 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.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2

2. Changes to the IPv4 Locally-Served DNS Zones Registry . . . . 2

2.1. RFC 6598 Zones . . . . . . . . . . . . . . . . . . . . . 2

3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5

4. Security Considerations . . . . . . . . . . . . . . . . . . . 5

5. Normative References . . . . . . . . . . . . . . . . . . . . 5

Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6

Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6

1. Introduction

[RFC6598] specifies that "Reverse DNS queries for Shared Address

Space addresses [100.64.0.0/10] MUST NOT be forwarded to the global

DNS infrastructure." [RFC6303] provides guidance on handling such

queries.

This document directs the IANA to add the IPv4 reverse zones

corresponding to 100.64.0.0/10, a netblock reserved in [RFC6598], to

the "IPv4 Locally-Served DNS Zone Registry" established in [RFC6303].

Unlike the addresses described in [RFC1918], which are not expected

to be seen by other parties, the addresses defined by [RFC6598] are

expected to be seen by parties other than those deploying the

addresses. Therefore, it is more crucial that recursive nameservers

default to serving these zones locally.

2. Changes to the IPv4 Locally-Served DNS Zones Registry

IANA has added the zones listed in "RFC 6598 Zones" (Section 2.1) to

the "IPv4 Locally-Served DNS Zone Registry".

2.1. RFC 6598 Zones

64.100.IN-ADDR.ARPA

65.100.IN-ADDR.ARPA

66.100.IN-ADDR.ARPA

67.100.IN-ADDR.ARPA

68.100.IN-ADDR.ARPA

69.100.IN-ADDR.ARPA

70.100.IN-ADDR.ARPA

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71.100.IN-ADDR.ARPA

72.100.IN-ADDR.ARPA

73.100.IN-ADDR.ARPA

74.100.IN-ADDR.ARPA

75.100.IN-ADDR.ARPA

76.100.IN-ADDR.ARPA

77.100.IN-ADDR.ARPA

78.100.IN-ADDR.ARPA

79.100.IN-ADDR.ARPA

80.100.IN-ADDR.ARPA

81.100.IN-ADDR.ARPA

82.100.IN-ADDR.ARPA

83.100.IN-ADDR.ARPA

84.100.IN-ADDR.ARPA

85.100.IN-ADDR.ARPA

86.100.IN-ADDR.ARPA

87.100.IN-ADDR.ARPA

88.100.IN-ADDR.ARPA

89.100.IN-ADDR.ARPA

90.100.IN-ADDR.ARPA

91.100.IN-ADDR.ARPA

92.100.IN-ADDR.ARPA

93.100.IN-ADDR.ARPA

94.100.IN-ADDR.ARPA

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95.100.IN-ADDR.ARPA

96.100.IN-ADDR.ARPA

97.100.IN-ADDR.ARPA

98.100.IN-ADDR.ARPA

99.100.IN-ADDR.ARPA

100.100.IN-ADDR.ARPA

101.100.IN-ADDR.ARPA

102.100.IN-ADDR.ARPA

103.100.IN-ADDR.ARPA

104.100.IN-ADDR.ARPA

105.100.IN-ADDR.ARPA

106.100.IN-ADDR.ARPA

107.100.IN-ADDR.ARPA

108.100.IN-ADDR.ARPA

109.100.IN-ADDR.ARPA

110.100.IN-ADDR.ARPA

111.100.IN-ADDR.ARPA

112.100.IN-ADDR.ARPA

113.100.IN-ADDR.ARPA

114.100.IN-ADDR.ARPA

115.100.IN-ADDR.ARPA

116.100.IN-ADDR.ARPA

117.100.IN-ADDR.ARPA

118.100.IN-ADDR.ARPA

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119.100.IN-ADDR.ARPA

120.100.IN-ADDR.ARPA

121.100.IN-ADDR.ARPA

122.100.IN-ADDR.ARPA

123.100.IN-ADDR.ARPA

124.100.IN-ADDR.ARPA

125.100.IN-ADDR.ARPA

126.100.IN-ADDR.ARPA

127.100.IN-ADDR.ARPA

3. IANA Considerations

Per this document, IANA has added the zones listed in "RFC 6598

Zones" (Section 2.1) to the "IPv4 Locally-Served DNS Zone Registry".

IANA is reminded that an insecure delegation for these zones is

required for compliance with [RFC6303] to break the DNSSEC chain of

trust.

4. Security Considerations

This document does not present additional security risks to the

Internet than those described in [RFC6303] and [RFC6598].

5. Normative References

[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,

and E. Lear, "Address Allocation for Private Internets",

BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996,

<http://www.rfc-editor.org/info/rfc1918>.

[RFC6303] Andrews, M., "Locally Served DNS Zones", BCP 163,

RFC 6303, DOI 10.17487/RFC6303, July 2011,

<http://www.rfc-editor.org/info/rfc6303>.

[RFC6598] Weil, J., Kuarsingh, V., Donley, C., Liljenstolpe, C., and

M. Azinger, "IANA-Reserved IPv4 Prefix for Shared Address

Space", BCP 153, RFC 6598, DOI 10.17487/RFC6598, April

2012, <http://www.rfc-editor.org/info/rfc6598>.

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Acknowledgements

The author would like to thank Joe Abley for his review comments.

Author's Address

M. Andrews

Internet Systems Consortium

950 Charter Street

Redwood City, CA 94063

United States

Email: marka@isc.org

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