DNS 5 REFUSED vs 11 DSOTYPENI
Both DNS 5 (REFUSED) and 11 (DSOTYPENI) 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, 11 means that dSO-TYPE Not Implemented. The DNS Stateful Operations (DSO) type in the request is not supported by the server.
Description
Query refused. The name server refuses to perform the requested operation for policy reasons.
When You See It
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.
How to Fix
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.
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.
Key Differences
DNS 5: Query refused. The name server refuses to perform the requested operation for policy reasons.
DNS 11: DSO-TYPE Not Implemented. The DNS Stateful Operations (DSO) type in the request is not supported by the server.
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 11 when your client attempted a DSO operation (like a keepalive or push subscription) that the server does not recognize or has not implemented.
When to Use Which
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 11 (DSOTYPENI): Verify that both client and server support the same DSO-TYPE. Upgrade the server software or fall back to traditional DNS queries.