If you run into a situation where you need to get to the IP address of the IPMI management interface of an ESX host, and the host is up and running, ssh to the system and run the below command. This should return the iDRAC/iLOM/etc IPv4 Address. This can be especially handy if documenting new environments.
enum_instances OMC_IPMIIPProtocolEndpoint root/cimv2 | grep IPv4Address