Port 53 UDP->TCP Fallback for large DNS queries

[Deefstomp]

Hello,

I wanted to ask what happens if I specify my local resolver only as a UDP resolver in the configuration. Will the Adguard Home Service still fall back to TCP if a DNS request is too large, as per the DNS standard defined?

I already tried to force this by using the virtual circuit feature of nslookup but this forces only TCP communication to Adguard. Not further down to my local unbound resolver (i sniffed that traffic with wireshark and so could confirm this).

[Deefstomp]

I would be really grateful for an answer, because Adguard Home is currently doing round robin load balancing between the same DNS resolver with both TCP and UDP (around 50/50). However, this is total nonsense because the majority of "my" DNS queries fit into a UDP packet and TCP is therefore used far too often (and is significantly slower / has way to much overhead for this task).