Author : Doreen Kasson
Topic Name : vSphere DNS Requirements
Publication Name : vSphere Installation and Setup
Product/Version : VMware vSphere/6.0
What ESXi Services are dependent on DNS?
I would say none. You may run it without it, but you will end up using IP address as identification everywhere. DNS is required as a best practice and to allow communication using names instead of IP address.
I recommendation is to use always DNS
Ensure that DNS reverse lookup returns an FQDN when queried with the IP address of the host machine on which vCenter Server is installed. When you install or upgrade vCenter Server, the installation or upgrade of the Web server component that supports the vSphere Web Client fails if the installer cannot look up the fully qualified domain name of the vCenter Server host machine from its IP address. Reverse lookup is implemented using PTR records.