What came first: the CNAME or the A record?

Post by jdmnd » Tue, Jan 20, 2026, 10:01 PM UTC

bashook wrote: post #109

mrmattyboy wrote: post #50

Earlier quoted context omitted.

I agree this doens't seem too ambiguous - it's "you may do this.." and they said "or we may do the reverse". If I say you're could prefix something.. the alternative isn't that you can suffix it. But also.. the programmers working on the software running one of the most important (end-user) DNS servers in the world: 1. Changes logic in how CNAME responses are formed 2. I assume some tests at least broke that meant th…

I was even more surprised to see that the RFC draft had original text from the author dating back to 2015. https://github.com/ableyjoe/draft-jabley-dnsop-ordered-answe... We used to say at work that the best way to get promoted was to be the programmer that introduced the bug into production and then fix it. Crazy if true here...

Post by paulddraper » Wed, Jan 21, 2026, 1:43 AM UTC

kiwijamo wrote: post #87

paulddraper wrote: post #19

> RFC 1034, published in 1987, defines much of the behavior of the DNS protocol, and should give us an answer on whether the order of CNAME records matters. Section 4.3.1 contains the following text: > If recursive service is requested and available, the recursive response to a query will be one of the following: > - The answer to the query, possibly preface by one or more CNAME RRs that specify aliases encountered o…

Some people (myself included) read that as "would ideally come first, but it is not neccessary that it comes first". The language is not clear IMHO and could be worded better.

Post by teddyh » Thu, Jan 22, 2026, 7:44 PM UTC

alt227 wrote: post #154

teddyh wrote: post #89

Cloudflare is well known for breaking DNS standards, and also then writing a new RFC to justify their broken behavior, and getting IETF to approve it. (The existence of RFC 8482 is a disgrace to everyone involved.) > To prevent any future incidents or confusion, we have written a proposal in the form of an Internet-Draft to be discussed at the IETF Of course.

This really depends on what side of the fence you are on. As a website host/maintainer, I am happy that the DNS 'ANY' query has been deprecated. I am sure if you are a network engineer or ISP, then it propbably annoys you no end.

Post by WGH_ » Sat, Jan 24, 2026, 4:08 PM UTC

zinekeller wrote: post #97

bpt3 wrote: post #60

Earlier quoted context omitted.

> Ends up in test environment for, what, a month.. nothing using getaddrinfo from glibc is being used to test this environment or anyone noticed that it was broken This is the part that is shocking to me. How is getaddrinfo not called in any unit or system tests?

As black3r mentioned ( https://news.ycombinator.com/item?id=46686096 ), it is likely rearranged by systemd, therefore only non-systemd glibc distributions are affected. I would hazard a guess that their test environment have both the systemd variant and the Unbound variants (Unbound technically does not arrange them, but instead reconstructs it according to RFC "CNAME restart" logic because it is a recursive resolver…

Post by teddyh » Wed, Jan 28, 2026, 7:05 PM UTC

alt227 wrote: post #168

teddyh wrote: post #165

Earlier quoted context omitted.

> As a website host/maintainer, I am happy that the DNS 'ANY' query has been deprecated. Why? What benefit does this bring you, or what negative consequence would otherwise have resulted for you?

Because without the ANY query it is much more difficult for people to immediately enumerate a full list of all subdomains and IPs for a given domain name. They need to be queried individually.