https://en.wikipedia.org/wiki/Happy_Eyeballs
Browsers even try other IPs and alternate between IPv4 and IPv6 before the connection is established.
Browsers even try other IPs and alternate between IPv4 and IPv6 before the connection is established.
The whole point of it is to connect to multiple A and AAAA records with a very short delay (250ms in chrome). The browsers use poll to get notified about the first established connection and then use it. So if one A/AAAA records IP is unreachable or slow it will use a another one. There will be no fallout (except maybe for clients that don't use something like happy eyeballs, but any browser does that) if you have multiple A/AAAA records and one of them is down.