A Common Operational Problem in DNS Servers - Failure To Communicate
draft-ietf-dnsop-no-response-issue-18
| The information below is for an old version of the document | |||
|---|---|---|---|
| Document | Type | Active Internet-Draft (dnsop WG) | |
| Authors | Mark Andrews , Ray Bellis | ||
| Last updated | 2020-03-22 | ||
| Replaces | draft-andrews-dns-no-response-issue | ||
| Stream | IETF | ||
| Intended RFC status | Best Current Practice | ||
| Formats | pdf htmlized (tools) htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Tim Wicinski | ||
| Shepherd write-up | Show (last changed 2019-11-17) | ||
| IESG | IESG state | IESG Evaluation | |
| Consensus Boilerplate | Yes | ||
| Telechat date |
Has enough positions to pass. |
||
| Responsible AD | Warren Kumari | ||
| Send notices to | "Tim Wicinski" <tjw.ietf@gmail.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
Network Working Group M. Andrews
Internet-Draft R. Bellis
Intended status: Best Current Practice ISC
Expires: September 23, 2020 March 22, 2020
A Common Operational Problem in DNS Servers - Failure To Communicate
draft-ietf-dnsop-no-response-issue-18
Abstract
The DNS is a query / response protocol. Failing to respond to
queries, or responding incorrectly, causes both immediate operational
problems and long term problems with protocol development.
This document identifies a number of common kinds of queries to which
some servers either fail to respond or else respond incorrectly.
This document also suggests procedures for zone operators to apply to
identify and remediate the problem.
The document does not look at the DNS data itself, just the structure
of the responses.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on September 23, 2020.
Copyright Notice
Copyright (c) 2020 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
(https://trustee.ietf.org/license-info) in effect on the date of
Andrews & Bellis Expires September 23, 2020 [Page 1]
Internet-Draft Failure To Communicate March 2020
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
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Consequences . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Common kinds of queries that result in no or bad responses. . 5
3.1. Basic DNS Queries . . . . . . . . . . . . . . . . . . . . 5
3.1.1. Zone Existence . . . . . . . . . . . . . . . . . . . 5
3.1.2. Unknown / Unsupported Type Queries . . . . . . . . . 5
3.1.3. DNS Flags . . . . . . . . . . . . . . . . . . . . . . 6
3.1.4. Unknown DNS opcodes . . . . . . . . . . . . . . . . . 6
3.1.5. TCP Queries . . . . . . . . . . . . . . . . . . . . . 6
3.2. EDNS Queries . . . . . . . . . . . . . . . . . . . . . . 6
3.2.1. EDNS Queries - Version Independent . . . . . . . . . 7
3.2.2. EDNS Queries - Version Specific . . . . . . . . . . . 7
3.2.3. EDNS Options . . . . . . . . . . . . . . . . . . . . 7
3.2.4. EDNS Flags . . . . . . . . . . . . . . . . . . . . . 7
3.2.5. Truncated EDNS Responses . . . . . . . . . . . . . . 8
3.2.6. DO=1 Handling . . . . . . . . . . . . . . . . . . . . 8
3.2.7. EDNS over TCP . . . . . . . . . . . . . . . . . . . . 8
4. Firewalls and Load Balancers . . . . . . . . . . . . . . . . 8
5. Scrubbing Services . . . . . . . . . . . . . . . . . . . . . 9
6. Whole Answer Caches . . . . . . . . . . . . . . . . . . . . . 10
7. Response Code Selection . . . . . . . . . . . . . . . . . . . 10
8. Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8.1. Testing - Basic DNS . . . . . . . . . . . . . . . . . . . 11
8.1.1. Is The Server Configured For The Zone? . . . . . . . 11
8.1.2. Testing Unknown Types . . . . . . . . . . . . . . . . 12
8.1.3. Testing Header Bits . . . . . . . . . . . . . . . . . 13
8.1.4. Testing Unknown Opcodes . . . . . . . . . . . . . . . 15
8.1.5. Testing TCP . . . . . . . . . . . . . . . . . . . . . 15
8.2. Testing - Extended DNS . . . . . . . . . . . . . . . . . 16
8.2.1. Testing Minimal EDNS . . . . . . . . . . . . . . . . 16
8.2.2. Testing EDNS Version Negotiation . . . . . . . . . . 17
8.2.3. Testing Unknown EDNS Options . . . . . . . . . . . . 17
8.2.4. Testing Unknown EDNS Flags . . . . . . . . . . . . . 18
8.2.5. Testing EDNS Version Negotiation With Unknown EDNS
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