Configuring ESXi hosts, vCenter Server systems, and the vSphere Web Client involves several tasks. Host ConfigurationBefore you create virtual machines on your hosts, you must configure the hosts to ensure that they have correct licensing, network and storage access, and security settings. Each type of host has a manual that provides information on the configuration for that host. Synchronizing Clocks on the vSphere NetworkVerify that all components on the vSphere network have their clocks synchronized. If the clocks on the machines in your vSphere network are not synchronized, SSL certificates, which are time-sensitive, might not be recognized as valid in communications between network machines. Configuring vCenter ServerYou can configure vCenter Server from the vSphere Web Client, including settings such as licensing, statistics collection, logging, and other settings. Using Enhanced Linked ModeEnhanced Linked Mode links multiple vCenter Server systems by using one or more Platform Services Controllers. With Enhanced Linked Mode, you can view and search across all linked vCenter Server systems. This mode replicates roles, permissions, licenses, and other key data across systems. Configuring Communication Among ESXi , vCenter Server, and the vSphere Web ClientBy default, the vSphere Web Client uses ports 80 and 443 to communicate with vCenter Server and ESXi hosts.