floFeb 6
Hm, da lege ich extra ne Subdomain an, weil ich dachte, dass ich darüber meine eigene Fedi-Instanz einrichten könnte, und dann finde ich in der "technischen Verwaltung" nur die Möglichkeit, DNS und CNAME für die Hauptdomain ändern zu können, nicht aber für die Subdomain 🤔

#Domain #Subdomain #CNAME #DNS #Webhosting
Gea-Suan LinFeb 3

https://blog.gslin.org/archives/2026/02/04/12876/cloudflare-%e7%9a%84-1-1-1-1-%e6%8a%8a-a-%e6%94%be%e5%9c%a8-cname-%e5%89%8d%e9%9d%a2%e6%90%9e%e7%88%86-glibc-%e7%9a%84-dns-resolver/

Cloudflare 的 1.1.1.1 把 A 放在 CNAME 前面搞爆 glibc 的 DNS resolver

#cloudflare #cname #dns #glib #linux #public #record #resolver #rfc #rr

Cloudflare 的 1.1.1.1 把 A 放在 CNAME 前面搞爆 glibc 的 DNS resolver

有陣子了，上個月的時候 Cloudflare 的 1.1.1.1 因為在改善記憶體用量，導致 A record 有可能在 CNAME record 前面，結果把 glibc 的 DNS resolver 炸了：「What came first: the CNAME or the A record?」，在 Hacker News 上也有些有趣的討論：「What came first:...

Gea-Suan Lin's BLOG
Show threadPontiff Fractal TiamJan 29

Still the Internet seems to be working despite Let's Encrypt putting IP addresses in certificate common name.

I. Am. Not. Surprised.

#pki #cname #letsencrypt

Hacker NewsJan 19

What came first: the CNAME or the A record?

https://blog.cloudflare.com/cname-a-record-order-dns-standards/

#HackerNews #CNAME #ARecord #DNS #DNSStandards #Cloudflare

What came first- the CNAME or the A record

A recent change to 1.1.1.1 accidentally altered the order of CNAME records in DNS responses, breaking resolution for some clients. This post explores the technical root cause, examines the source code of affected resolvers, and dives into the inherent ambiguities of the DNS RFCs.

The Cloudflare Blog
Some Bits: Nelson's LinkblogJan 15
CNAME vs A record: Cloudflare outage report talks about a subtle wrinkle in DNS, where the order of the records matters when it probably shouldn't
https://blog.cloudflare.com/cname-a-record-order-dns-standards/
#postmortem #cloudflare #outage #cname #dns #+
What came first- the CNAME or the A record

A recent change to 1.1.1.1 accidentally altered the order of CNAME records in DNS responses, breaking resolution for some clients. This post explores the technical root cause, examines the source code of affected resolvers, and dives into the inherent ambiguities of the DNS RFCs.

The Cloudflare Blog
Show threadPontiff Fractal TiamNov 19

It's been over half a year and the Internet still seems to be working.

Here's your regular reminder that #cname in #x509 is almost always irrelevant for the validation. If someone is using it, they are doing it wrong.

Henning UhleOct 31

Wieder zurück ausm Urlaub. Aber mal was anderes:

Hier gibt es doch viele, die bei #Hetzner hosten, ja? Und da nutzen doch auch viele #WordPress ja? Und vielleicht ist da auch wer mit #MailPoet darunter und könnte mir weiterhelfen.

Ich soll zwei #CNAME-Einträge für MailPoet anlegen. Und bei Hetzner in der DNS-Konsole hab ich das richtig angelegt. Mit "dkim1.sendingservice.net" als Wert. Bei MailPoet kommt das an mit meiner Domain dahinter, also "dkim1.sendingservice.net.henning-uhle.eu". Wieso passiert das? Und wie stelle ich das ab?

Vielen Dank schonmal. Und gern #boost und so.

Vito Sartori (ヴィト) 🦊Oct 10

So something really weird happened today. I received an abuse report for a dormant domain I have.

The report pointed to a CNAME subdomain pointing to [org].github.io. The org is still there, the repository that was serving that subdomain is still there, but accessing it led to a phishing page.

Anyone has seen anything like that? No activity on the github organisation, nothing on audit logs of the affected domain. Nothing makes sense.

#github #infosec #dns #cname #phishing

Jun WongSep 23

New post: How to Set Up Free SSL For Your Websites (Cloudflare!) Why is SSL important for websites?

You’ve probably notice https://junsungwong.com/2025/08/27/how-to-set-up-free-ssl-for-your-websites-cloudflare/ #ARecord #BeginnerFriendly #Cloudflare #CNAME

Show threadPontiff Fractal TiamSep 18, 2025
I was told that I'm too dumb to understand the threat of putting IP addresses in #x509 #cname, and after two months, the Internet seems to be working just fine.