DNS

DNS 0 NOERROR vs 23 BADCOOKIE

Both DNS 0 (NOERROR) and 23 (BADCOOKIE) belong to the DNS Response Codes (RCODEs) category. 0 indicates that no error condition. The query completed successfully and the response contains the requested data. Meanwhile, 23 means that bad or missing server cookie. The DNS COOKIE option in the request is absent, malformed, or does not match the server's expected value.

Descripción

No error condition. The query completed successfully and the response contains the requested data.

Cuándo lo verás

This is the normal, successful response to any DNS query — the name was resolved and the answer section contains the requested records.

Cómo solucionarlo

No fix needed. RCODE 0 means the DNS lookup succeeded as expected.

Descripción

Bad or missing server cookie. The DNS COOKIE option in the request is absent, malformed, or does not match the server's expected value.

Cuándo lo verás

Your resolver sent a query without a valid server cookie, or the cookie has expired. This is part of the DNS COOKIE mechanism to prevent spoofed-source attacks.

Cómo solucionarlo

Retry the query — most resolvers automatically learn the correct server cookie from the first response. If the error persists, ensure your resolver supports RFC 7873 DNS Cookies.

Diferencias clave

1.

DNS 0: No error condition. The query completed successfully and the response contains the requested data.

2.

DNS 23: Bad or missing server cookie. The DNS COOKIE option in the request is absent, malformed, or does not match the server's expected value.

3.

You encounter 0 when this is the normal, successful response to any DNS query — the name was resolved and the answer section contains the requested records.

4.

You encounter 23 when your resolver sent a query without a valid server cookie, or the cookie has expired. This is part of the DNS COOKIE mechanism to prevent spoofed-source attacks.

Cuándo usar cada uno

For 0 (NOERROR): No fix needed. RCODE 0 means the DNS lookup succeeded as expected. For 23 (BADCOOKIE): Retry the query — most resolvers automatically learn the correct server cookie from the first response. If the error persists, ensure your resolver supports RFC 7873 DNS Cookies.

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