New in Simple DNS Plus

New features / updates in v. 9.1:

JavaScript plug-in

Write your own custom logic for DNS query processing in JavaScript. Your script code runs efficiently via Google's V8 JavaScript engine - the same that powers Chrome and Node.js.

The JavaScript code can be as simple or complex as needed - for example:

The plug-in supports storing the JavaScript code in a separate file (optional), which lets you edit the code in the editor of your choice - for example Visual Studio Code to get JavaScript syntax highlighting etc.

The plug-in also supports connecting debuggers (such as Chrome DevTools) to debug your JavaScript code running in Simple DNS Plus live:

This plug-in is automatically installed with Simple DNS Plus v. 9.1.

Read more about this at

New asynchronous plug-in interface

The programming interface for plug-ins has been updated use the asynchronous programming model (async/await).

This improves performance by allowing simple plug-ins (like "Fixed IP address") to execute directly in the main thread, while making it easier to take advantage of asynchronous operations with I/O bound plug-ins (like "MS SQL Server").

The new plug-in interface also shares more code with the main Simple DNS Plus program, so that fewer conversions are needed when communicating between the plug-in and the program, which also improves performance.

Plug-ins included with the Simple DNS Plus installer are updated automatically, but you will need to download new versions of any downloadable plug-ins (v. 9.1 updates have been published for all of them), and any custom developed plug-ins will need to be re-programmed to work with the new interface.

Plug-in query order enhanced

It is now possible to have some plug-ins queried before local zones and other plug-ins queried after local zones (used to be either all plug-ins before or all plugs-ins after):

Miscellaneous updates

  • New plug-in DNS Request rule "Server is authoritative (AA)". Can be used to only "ask" the plug-in when the server is (or is not) authoritative (has a zone) for the requested name. (only works for plug-ins listed after [LOCAL DNS ZONES] - see "Plug-in query order enhanced" above).
  • The "Automatic SPF records" feature (Options dialog / DNS / Local Zones / Automatic SPF) has been removed. A new Auto SPF plug-in is now available to provide this functionality.
  • "Maximum inbound DNS TCP connections" option (Options dialog / DNS / Inbound requests section) changed to "...per source IP address". To avoid blocking legitimate connections from other IP addresses.

Breaking changes

  • The programming interface for plug-ins has changed (see "New asynchronous plug-in interface" above).
  • The "Automatic SPF records" feature has been replaced by a new plug-in (see Miscellaneous above). If you were using this feature, you will need to re-configure this with the plug-in.
24 Mar 2022 22:58 UTC
Duane Shippy
We are seeing errors after upgrading to version 9.1. Started the day we did the upgrade from an older version of Simple DNS. Here's the error in the Windows Event Log (error 5774)

The dynamic registration of the DNS record ' 600 IN A x.x.x.x' failed on the following DNS server:

DNS server IP address: y.y.y.y (this is our primary domain controller)
Returned Response Code (RCODE): 0
Returned Status Code: 9502

For computers and users to locate this domain controller, this record must be registered in DNS.

Determine what might have caused this failure, resolve the problem, and initiate registration of the DNS records by the domain controller. To determine what might have caused this failure, run DCDiag.exe. To learn more about DCDiag.exe, see Help and Support Center. To initiate registration of the DNS records by this domain controller, run 'nltest.exe /dsregdns' from the command prompt on the domain controller or restart Net Logon service.
Or, you can manually add this record to DNS, but it is not recommended.

Error Value: Bad DNS packet.
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