RFC 4343, "Domain Name System (DNS) Case Insensitivity Clarification", January 2006Source of RFC: dnsext (int)
Errata ID: 5112
Status: Held for Document Update
Publication Format(s) : TEXT
Reported By: Rich Tom
Date Reported: 2017-09-12
Held for Document Update by: Warren Kumari
Date Held: 2017-09-13
Section 3 says:
comparisons on name lookup for DNS queries should be case insensitive
It should say:
comparisons on name lookup for DNS queries must be case insensitive
--- Original report ---
Some authoritative DNS servers and/or mitigation devices/software silently drop queries that have uppercase letters in them. Furthermore, the clarification of the case insensitive comparison in the following two sentences after that particular sentence use the term MUST. I suspect some readers of the RFC are reading the word "should" and aren't reading the rest of the paragraph.
---- WK Update ----
The full quote is: "According to the original DNS design decision, comparisons on name
lookup for DNS queries should be case insensitive [STD13]. ", and the title of this (RFC4343) is "Domain Name System (DNS) Case Insensitivity Clarification" -- seeing as the whole point of this document is to clarify the original spec, I think that readers will read the RFC2119 bits.
However, I do agree that this could be better worded, and future updates of this document should probably reword this to make it clearer.