On 04. 05. 20 20:52, Paul Hoffman wrote:
On May 4, 2020, at 11:34 AM, Paul Vixie <paul@redbarn.org> wrote:
so, to the question i think fred meant to ask, TCP fallback is an expectation we can have, and it's full-resolver behaviour that we can rely on, even if some full resolvers don't support TCP fallback and rely on UDP fragmentation.
In my mind, it is fine to say that RSSAC (or some other RSS-y body) expects resolvers to be able to do TCP fallback. That is, some or all of the RSS will act based on that expectation being fulfilled.
To me this is no-brainer. DNS clients need to follow the DNS protocol to be interoperable with DNS servers, RSS included. To emphasise this I propose to extend the last FAQ paragraph to read like this: For full interoperability DNS-over-TCP is nowadays mandatory to implement. For additional information please refer to RFC 7766. -- Petr Špaček @ CZ.NIC