Using Test Management Network to Resolve the DNS Host Name Is Unreliable
Details
When you test the network configuration by using the local user interface of your ESX Server 3i host and enter your host's name, the DNS host name resolution operation always succeeds, even if you enter an invalid host name.
Solution
Do not rely on the results of the DNS host name resolution test that the Test Management Network tool performs using the default host name value.
Using the Test Management Network to test connectivity to other devices on the network is reliable.