The vSphere 4.0 service console and management interface require a network interface. The service console does not automatically use the first interface with a live connection. Instead, it allows you to select one during the installation. It defaults to vmnic0.
Perform the following tasks before beginning the ESX 4 installation.
Refer to your service manual for information about the network connectors on your server.
VMware documentation in How to Obtain VMware Installation and Administration Documentation for information about the ESX4 service console and management interface.