DNS/oarc.net/txt/OpenDNSについて、ここに記述してください。
$ dig rs.dns-oarc.net txt @208.67.222.222
; <<>> DiG 9.11.1 <<>> rs.dns-oarc.net txt @208.67.222.222 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50013 ;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;rs.dns-oarc.net. IN TXT ;; ANSWER SECTION: rs.dns-oarc.net. 60 IN CNAME rst.x1384.rs.dns-oarc.net. rst.x1384.rs.dns-oarc.net. 59 IN CNAME rst.x1394.x1384.rs.dns-oarc.net. rst.x1394.x1384.rs.dns-oarc.net. 58 IN CNAME rst.x1353.x1394.x1384.rs.dns-oarc.net. rst.x1353.x1394.x1384.rs.dns-oarc.net. 57 IN TXT "2620:0:cca::67 DNS reply size limit is at least 1394" rst.x1353.x1394.x1384.rs.dns-oarc.net. 57 IN TXT "2620:0:cca::67 sent EDNS buffer size 1410" rst.x1353.x1394.x1384.rs.dns-oarc.net. 57 IN TXT "Tested at 2017-07-15 06:51:39 UTC" ;; Query time: 1466 msec ;; SERVER: 208.67.222.222#53(208.67.222.222) ;; WHEN: Sat Jul 15 15:51:39 JST 2017 ;; MSG SIZE rcvd: 281