Re: does firefox failover on DNS Round Robin?

On Fri, 2 Nov 2018, [email protected] wrote:

> There are some RFCs about Happy-Eyeballs: RFC 8305 which obsoletes RFC 6555.

Firefox doesn't really implement RFC 8305 though, which specifically says:

   "Implementations SHOULD NOT wait for both families of answers to return
    before attempting connection establishment"

... which thus rules out using a single getaddrinfo() to get both A and AAAA 
records.

When doing DNS-over-HTTPS instead, Firefox will at least do the different 
resolves separately and *can* act as soon as the first response comes back. 
(But will only do so by default if the A entries return first, for practical 
reasons.)

Firefox's Happy-Eyeballs is more in the RFC 6555 style.

-- 

  / daniel.haxx.se