DNS 11 DSOTYPENI vs 18 BADTIME
Both DNS 11 (DSOTYPENI) and 18 (BADTIME) belong to the DNS Response Codes (RCODEs) category. 11 indicates that dSO-TYPE Not Implemented. The DNS Stateful Operations (DSO) type in the request is not supported by the server. Meanwhile, 18 means that signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
Description
DSO-TYPE Not Implemented. The DNS Stateful Operations (DSO) type in the request is not supported by the server.
When You See It
Your client attempted a DSO operation (like a keepalive or push subscription) that the server does not recognize or has not implemented.
How to Fix
Verify that both client and server support the same DSO-TYPE. Upgrade the server software or fall back to traditional DNS queries.
Description
Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
When You See It
The clocks on the DNS client and server are too far apart (usually more than 5 minutes), causing TSIG signature validation to fail.
How to Fix
Synchronize clocks on both machines using NTP. Check that the TSIG fudge value (allowed skew) is reasonable — the default 300 seconds is usually sufficient.
Key Differences
DNS 11: DSO-TYPE Not Implemented. The DNS Stateful Operations (DSO) type in the request is not supported by the server.
DNS 18: Signature out of time window. The TSIG signature timestamp is outside the allowed clock skew, indicating a time synchronization issue.
You encounter 11 when your client attempted a DSO operation (like a keepalive or push subscription) that the server does not recognize or has not implemented.
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.
When to Use Which
For 11 (DSOTYPENI): Verify that both client and server support the same DSO-TYPE. Upgrade the server software or fall back to traditional DNS queries. 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.