There is another addition to the downloads section that will check the availability of a DNS server by running a "nslookup" type test.  This MP uses a 3rd Party DLL called Simple DNS Resolver to make the DNS calls.  The VBscript that is included in this MP will test a FQDN using the nameservers specified and compares it to an IP address that is supplied as well.   Not only can you really test the availability of the target DNS service, you can also use it to verify that a DNS record is returning the proper IP address.

After importing the MP, you can view the sample rules by changing the scope of the Rules view in the Authoring pane to Management Server.  The two rules to look for is called DNS Check - Example and DNS Check Failure.  The DNS Check - Example contains the script that will check DNS availability and the DNS Check Failure rule checks for the event IDs logged by the DNS Check - Example rule.

You can download the Simple DNS Resolver from the author’s site at kartmann.org and you can download the sample MP located in our Downloads section called DNS Check MP.