TRUNCATED_FELL_BACK_TO_TCP

info

The record is too large for a single UDP response, so it was retrieved over TCP. This is normal for 2048-bit keys.

An observation. Whether it matters depends on what the domain is for.

How we know

tcp.test
Both sides of the boundary, measured rather than assumed: a real 2048-bit key is a 483-byte response and must NOT be reported as truncated, while a 4096-bit key exceeds 512 and must be. A 4.4 KB TXT truncates even at an advertised 4096.