DNS 5 REFUSED vs 19 BADMODE
Both DNS 5 (REFUSED) and 19 (BADMODE) belong to the DNS Response Codes (RCODEs) category. 5 indicates that query refused. The name server refuses to perform the requested operation for policy reasons. Meanwhile, 19 means that bad TKEY Mode. The TKEY mode field contains a value not supported by the server.
説明
Query refused. The name server refuses to perform the requested operation for policy reasons.
このコードが表示される場合
The server rejected your query due to access control — for example, a recursive resolver that only serves its own network, or a zone transfer blocked by ACL.
解決方法
Check the server's allow-query, allow-recursion, or allow-transfer ACLs. If you are not authorized to use this resolver, switch to a public DNS service.
説明
Bad TKEY Mode. The TKEY mode field contains a value not supported by the server.
このコードが表示される場合
Your client attempted a TKEY key exchange using a mode (e.g., Diffie-Hellman, GSS-API) that the server does not support or has not been configured for.
解決方法
Check which TKEY modes the server supports and configure your client to use a compatible mode. GSS-TSIG (mode 3) is the most widely deployed.
主な違い
DNS 5: Query refused. The name server refuses to perform the requested operation for policy reasons.
DNS 19: Bad TKEY Mode. The TKEY mode field contains a value not supported by the server.
You encounter 5 when the server rejected your query due to access control — for example, a recursive resolver that only serves its own network, or a zone transfer blocked by ACL.
You encounter 19 when your client attempted a TKEY key exchange using a mode (e.g., Diffie-Hellman, GSS-API) that the server does not support or has not been configured for.
どちらをいつ使うか
For 5 (REFUSED): Check the server's allow-query, allow-recursion, or allow-transfer ACLs. If you are not authorized to use this resolver, switch to a public DNS service. For 19 (BADMODE): Check which TKEY modes the server supports and configure your client to use a compatible mode. GSS-TSIG (mode 3) is the most widely deployed.