[toast0]

If you're behind a big CGNAT and Google knows it, they might intentionally return multiple addresses to have more capacity.

Each service port (IP:Port) can only receive 64k connections from each NAT IP, returning more IPs from DNS makes more connections available. Google is a very popular service, so it makes sense to do. (Less so for v6, though)

Alternately, if they can't get a good feel for where you are, returning A records for multiple locations makes sense, too.

No idea why 4 AAAA vs 6 A; Google runs dual stacked and I'd expect the same number of records for both; IIRC, 8 AAAA will usually fit in a 512 byte udp reply, and anyway DNS64 might expand As into AAAAs, so you have to gauge sizes with those anyway.

[ignoramous]

> Each service port (IP:Port) can only receive 64k connections from each NAT IP

Interestingly, for Tor, the lowest common denominator local port exhaustion threshold at exit is 16384.

https://spec.torproject.org/proposals/348-udp-app-support.ht...