DNS

DNS 0 NOERROR vs 18 BADTIME

Both DNS 0 (NOERROR) and 18 (BADTIME) 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, 18 means that signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.

Описание

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

Когда вы это видите

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

Как исправить

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

Описание

Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.

Когда вы это видите

The clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.

Как исправить

Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.

Ключевые различия

1.

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

2.

DNS 18: Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.

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 18 when the clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.

Когда что использовать

For 0 (NOERROR): No fix needed. RCODE 0 means the DNS lookup succeeded as expected. For 18 (BADTIME): Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.

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