Imagine the scenario: You have a server that you installed ESX server on. You configured it for your local network. Then you shipped the box to a remote location. Someone in the lab connected the box to a switch. There is no human present when you are working on the system remotely. How do you reconfigure the network parameters?
In my case, for this DELL servers, I used DRAC to reach out to the box. Then I logged into the system and reconfigured network using esxcfg-vswif. The network interface that needs to be configured is vswif0.
The instructions are well documented here. The only piece missing is the edit of /etc/hosts, if the IP address at the old location is configured there (too).