DNS 5 REFUSED vs 20 BADNAME
Both DNS 5 (REFUSED) and 20 (BADNAME) 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, 20 means that duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
描述
Query refused. The name server refuses to perform the requested operation for policy reasons.
何时出现
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.
如何修复
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.
描述
Duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
何时出现
A TKEY key establishment failed because a key with the same name already exists on the server from a previous session that was not properly cleaned up.
如何修复
Use a unique key name for each TKEY session (e.g., append a timestamp or random suffix). Delete stale keys on the server if they are no longer needed.
主要区别
DNS 5: Query refused. The name server refuses to perform the requested operation for policy reasons.
DNS 20: Duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
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 20 when a TKEY key establishment failed because a key with the same name already exists on the server from a previous session that was not properly cleaned up.
何时使用哪个
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 20 (BADNAME): Use a unique key name for each TKEY session (e.g., append a timestamp or random suffix). Delete stale keys on the server if they are no longer needed.