DNS 3 NXDOMAIN vs 20 BADNAME
Both DNS 3 (NXDOMAIN) and 20 (BADNAME) belong to the DNS Response Codes (RCODEs) category. 3 indicates that non-Existent Domain. The queried domain name does not exist in the DNS namespace. Meanwhile, 20 means that duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
説明
Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
このコードが表示される場合
The domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
解決方法
Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated.
説明
Duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
このコードが表示される場合
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.
解決方法
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.
主な違い
DNS 3: Non-Existent Domain. The queried domain name does not exist in the DNS namespace.
DNS 20: Duplicate key name. The key name in a TKEY negotiation is already in use or conflicts with an existing key.
You encounter 3 when the domain has no DNS records at all — either it was never registered, has expired, or you have a typo in the hostname.
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.
どちらをいつ使うか
For 3 (NXDOMAIN): Double-check the domain spelling. If you own the domain, verify your registrar settings and ensure the nameservers are correctly delegated. 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.