One of the most popular tools that I have developed over the last few years is DNSLint.  This tool shipped with the Support Tools on the Windows Server 2003 CD and has been available for download from the download center on www.microsoft.com for a few years.

I frequently get asked where the idea for this tool came from, so I thought I would post the story here.  I developed this tool when I worked on the Enterprise Platform Support Networking team in Product Support Services (here at Microsoft).  One of the services that this team supports is DNS.  After Windows 2000 shipped it seemed like almost every customer I talked to needed help designing a DNS namespace or had implemented a design that they needed help with.  The primary reason for this is that Windows 2000 requires DNS for Active Directory and many customers were upgrading from Windows NT 4.0 which did not require DNS for domain building purposes.  Many people needed help with DNS during this transition period.

After spending hours with nslookup troubleshooting lame delegation issues, I decided to build a tool to automate the process and save everyone some time.  DNSLint was born.  Travis Adams from the Enterprise Platform Support Directory Services team asked me to add a feature to help troubleshoot Active Directory replication issues caused by missing or inconsistent DNS records.  Then I added a feature that allows you to query all the DNS records specified in an input file.  With this feature you can check all the DNS records for all of your critical servers (domain controllers, web servers, SQL servers, etc) on every DNS server that should know about them in a very short time frame.

I receive e-mail about DNSLint weekly.  A frequently asked question I get about this tool is not a technical question at all:  Is the Lint in DNSLint an acronym and if so…what does it mean?  Just to clear this up…lint is something you find in your blue jeans after they come out of the dryer.  When you find lint, it is useless and sort of embarrassing…so you quickly throw it away.  Not unlike outdated or inaccurate DNS records for important systems. ;>)

You can read all the technical details about DNSLint in this Knowledge Base article: 

http://support.microsoft.com/?kbid=321045

I also recorded a webcast for your listening and viewing pleasure:

http://support.microsoft.com/default.aspx?scid=kb;en-us;329982

Also, there are lots of good DNS resources at the DNS center:

http://www.microsoft.com/Windows2000/technologies/communications/dns/default.asp