Aggressive Use of DNSSEC-Validated Cache
RFC 8198
| Document | Type |
RFC - Proposed Standard
(July 2017; No errata)
Updates RFC 4035
|
|
|---|---|---|---|
| Last updated | 2018-12-20 | ||
| Replaces | draft-fujiwara-dnsop-nsec-aggressiveuse | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Tim Wicinski | ||
| Shepherd write-up | Show (last changed 2017-05-09) | ||
| IESG | IESG state | RFC 8198 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Terry Manderson | ||
| Send notices to | "Tim Wicinski" <tjw.ietf@gmail.com> | ||
| IANA | IANA review state | IANA OK - No Actions Needed | |
| IANA action state | No IANA Actions | ||
Internet Engineering Task Force (IETF) K. Fujiwara
Request for Comments: 8198 JPRS
Updates: 4035 A. Kato
Category: Standards Track Keio/WIDE
ISSN: 2070-1721 W. Kumari
Google
July 2017
Aggressive Use of DNSSEC-Validated Cache
Abstract
The DNS relies upon caching to scale; however, the cache lookup
generally requires an exact match. This document specifies the use
of NSEC/NSEC3 resource records to allow DNSSEC-validating resolvers
to generate negative answers within a range and positive answers from
wildcards. This increases performance, decreases latency, decreases
resource utilization on both authoritative and recursive servers, and
increases privacy. Also, it may help increase resilience to certain
DoS attacks in some circumstances.
This document updates RFC 4035 by allowing validating resolvers to
generate negative answers based upon NSEC/NSEC3 records and positive
answers in the presence of wildcards.
Status of This Memo
This is an Internet Standards Track document.
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
Internet Standards is available in Section 2 of RFC 7841.
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/rfc8198.
Fujiwara, et al. Standards Track [Page 1]
RFC 8198 NSEC/NSEC3 Usage July 2017
Copyright Notice
Copyright (c) 2017 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. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 3
4. Background . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Aggressive Use of DNSSEC-Validated Cache . . . . . . . . . . 6
5.1. NSEC . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. NSEC3 . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.3. Wildcards . . . . . . . . . . . . . . . . . . . . . . . . 6
5.4. Consideration on TTL . . . . . . . . . . . . . . . . . . 7
6. Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Update to RFC 4035 . . . . . . . . . . . . . . . . . . . . . 8
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
9. Security Considerations . . . . . . . . . . . . . . . . . . . 9
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
10.1. Normative References . . . . . . . . . . . . . . . . . . 9
10.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Detailed Implementation Notes . . . . . . . . . . . 11
Appendix B. Procedure for Determining ENT vs. NXDOMAIN with NSEC 11
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
Fujiwara, et al. Standards Track [Page 2]
RFC 8198 NSEC/NSEC3 Usage July 2017
1. Introduction
A DNS negative cache exists, and is used to cache the fact that an
RRset does not exist. This method of negative caching requires exact
matching; this leads to unnecessary additional lookups, increases
latency, leads to extra resource utilization on both authoritative
and recursive servers, and decreases privacy by leaking queries.
This document updates RFC 4035 to allow resolvers to use NSEC/NSEC3
resource records to synthesize negative answers from the information
they have in the cache. This allows validating resolvers to respond
with a negative answer immediately if the name in question falls into
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