Plug-Ins Overview

Simple DNS Plus v. 5.2
Copyright © 1999-2013 JH Software ApS

Simple DNS Plus has a plug-in system for providing additional/optional functionality. This allows us and 3rd parties to develop new features without cluttering the base product, and allowing users to select which of these features they want - or don't want.


The standard Simple DNS Plus installation comes with the following plug-ins:


DHCP Server
A basic DHCP server which provides IPv4 addresses and settings to local computers and devices. The DHCP data is also used to serve DNS requests (forward and reverse) making it very simple to locate any local DHCP client by name on a local network.
For details see KB1216.
Domain Blacklist
Redirects DNS requests for domain names on a blacklist. Can be used to block banner ads, malicious web-sites, porn web-sites, etc. Doing this at a central DNS server makes it easy to enforce company/family policy for your entire network. You can direct browser requests for listed entries either to a dummy IP address, or to an IP address of your own web-server where you serve up some type of  "not allowed" message.
For details see KB1253.
DynDNS Service
Makes it easy to run your own "DynDNS" service (just like,,, etc.).
Besides from running a public DynDNS service, there are many possible uses for this. For example making it easy to connect with company road warriors, branch offices, etc.
A DynDNS service makes it possible to connect, using a static host name, to any kind of service including web-server, mail-server, remote desktop, VPN, etc. running on a computer with a dynamic Internet IP address.
For details see KB1267.
Fixed Host Name
Serves a fixed host name - either to all DNS requests as a CNAME (alias), or to DNS requests for MX, NS, and/or PTR-records.
For details see KB1263.
Fixed IP Address
Serves a fixed IP address (IPv4 and/or IPv6) to all DNS requests for host records (A / AAAA).
This can be used as a simple way to host DNS records.
For details see KB1261.
Hosts File
Serves host (A / AAAA) and reverse (PTR) DNS records from a standard hosts file.
For details see KB1210.
HTTP Redirector
Redirects HTTP requests for specified host names (and optionally all sub-names).
Redirection can be done either "cloaked" in a frame page (redirect URL not visible in browser) or through a standard 302/301 status response.
The redirect-to URL can be either relative (requested path/query appended) or an exact URL with optional substitutions for host name, path and/or query string.
This can be used for example to redirect to a web-server running on a dynamic IP address (redirecting to a host name updated by a dynamic DNS service) and/or to redirect to a web-server on a non-standard port number (like ""). These types of redirection services are often offered by domain name registrars and resellers.
For details see KB1258.
Ignore DNS Request
Instructs Simple DNS Plus to ignore (not answer) all DNS requests processed by the plug-in.
This can be used to ignore requests from specific IP addresses, for specific domain names, record types, etc.
As an example, you could configure it to ignore DNS requests from IP addresses listed by a blacklist plug-in.
For details see KB1280.
MS SQL Server
Queries a Microsoft SQL Server for host records and optionally reverse records.
For details see KB1211.
MS SQL Server Plus
Queries a Microsoft SQL Server for one or more DNS records of any type.
(Requires an "Unlimited zones" license)
For details see KB1249.
Regular Expressions
Use Regular Expressions to pair host domain names to IP addresses. More powerful and flexible than simple wildcard records.
For details see KB1212.
Used to skip other plug-in instances when processing DNS requests.
This is typically used to apply one or more conditions (in the "DNS Requests" tab) to several other plug-ins at the same time.
For details see KB1262.


Weighted Round Robin
Serves IP addresses (A / AAAA records)  for a host name round robin from a weighted list.
IP addresses are rotated so that the first visitor gets one IP address, the next visitor another IP address, etc. However IP addresses with higher weight values are served more often than IP addresses with lower weight values. This makes it possible for example to send more traffic to high capacity servers in a round robin set.
For details see KB1252.


Additional plug-ins are available for download from


Plug-ins are instantiated in the Options dialog / Plug-Ins section.


Some plug-ins (including the DHCP Server plug-in) have their own View - a dockable sub-window in the main window.

The plug-in architecture is open for users and 3rd parties interested in developing their own plug-ins.
In short, this is all based on the .NET Framework 2.0 interfaces found in the "sdnsplugin.dll" file supplied with Simple DNS Plus. More information about developing plug-ins is available on-line in KB1281.