You may have spotted the 512 in something like the following (after ``EDNS ... udp:``)::
- $ dig example.com @9.9.9.9
+ $ dig example.com @127.0.0.1
- ; <<>> DiG 9.11.5-P4-5.1+deb10u3-Debian <<>> example.com @9.9.9.9
+ ; <<>> DiG 9.11.5-P4-5.1+deb10u3-Debian <<>> example.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20155
example.com. 43200 IN A 93.184.216.34
;; Query time: 86 msec
- ;; SERVER: 9.9.9.9#53(9.9.9.9)
+ ;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Apr 15 13:56:34 CEST 2021
;; MSG SIZE rcvd: 56
To see the buffer size the Recursor is reporting to authoritatives, ask an authoritative::
- $ dig txt header.lua.powerdns.org +short @9.9.9.9
+ $ dig txt header.lua.powerdns.org +short @127.0.0.1
"id: 52938, aa: false, rd: false, ad: false, cd: false, do: true, ednsbufsiz: 1232, tcp: false"