Get the latest tech news

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.

None

Get the Android app

Or read this on Hacker News

Read more on:

Photo of record

record

Photo of CNAME

CNAME

Related news:

News photo

2025 was the third hottest year on record

News photo

TSMC 'very nervous' about AI bubble concerns despite another record-setting quarter, but assured of demand — CEO says careless investment 'would be a disaster for TSMC for sure,' company will invest $52-$56 billion in capex

News photo

Novo Fund to Donate Record $860 Million in New Bioscience Grant