DNS-OARCについて、ここに記述してください。

https://www.dns-oarc.net/oarc/services/replysizetest

Recent increases in DNSSEC deployment are exposing problems with DNS resolvers that cannot receive large responses. The maximim reply size between a DNS server and resolver may be limited by a number of factors:

• If a resolver does not support the Extension Mechanisms for DNS (EDNS),
  • replies are limited to 512 bytes.
• The resolver may be behind a firewall that blocks IP fragments.
• Some DNS-aware firewalls block responses larger than 512 bytes.

The BIND resolver, since version 9.5.0, includes a feature to decrease its advertised EDNS receive buffer size (down to 512) when its queries time out.

1.

https://tools.ietf.org/id/draft-ietf-dnsext-rfc2671bis-edns0-09.

htmlExtension Mechanisms for DNS (EDNS(0)) draft-ietf-dnsext-rfc2671bis-edns0-09