Most folks working in IT are familiar with using the ping command to test network connectivity. If you are trying to test the connection between your computer and another, you can ping it from a Command Prompt and test whether or not it replies. This assumes that the firewalls in your computers and network allow the ping to respond correctly, which generally is true. If you are inside a domain network and ping a device by its name, that name resolves to an IP address, which is the device's address on the network. But what tells your computer which IP address corresponds to which name? This is where DNS comes in. Any time your computer makes a request for a name, whether it is you pinging another computer or your Outlook e-mail client requesting the name of your Exchange Server, your computer always reaches out to your network's DNS servers and asks, "How do I get to this name?".

DNS contains a list of records that tell the computers in your network what...