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Showing posts from January, 2019

Are you ready for DNS Flag Day?

They were only trying to do the right thing. When a recursive DNS server issues a query using DNS Extensions (EDNS) to another DNS server and the answer indicates a format error or there is no answer at all, developers of various recursive DNS server implementations created workarounds such as reissuing the query without extensions or querying another server authoritative for the same zone. This philosophy centered on coding the recursive server to fetch an answer even if it meant trying to ask in many different forms. While a noble pursuit in "doing what it takes" to obtain an answer, these and similar workarounds introduce additional queries of various formats and additional processing requirements on the recursive server. These inefficiencies, while intended to satisfy the requirement of answering the query, are needlessly reducing performance and scalability of the Internet. And as more extension features are introduced, complexity of recursive server software will incr