DNS
21 BADALG
Algorithm not supported. The cryptographic algorithm specified in the TKEY or SIG record is not supported by the server.
このコードが表示された場合
Your TKEY negotiation or DNSSEC operation requested an algorithm (e.g., HMAC-SHA512) that the server has not been compiled with or configured to accept.
修正方法
Use a mutually supported algorithm. HMAC-SHA256 is widely supported for TSIG; for DNSSEC, check the server's supported algorithm list with its documentation.