To install or upgrade ESXi, your system must meet specific hardware and software requirements. What to read next ESXi Hardware RequirementsMake sure the host meets the minimum hardware configurations supported by ESXi6.5. Supported Remote Management Server Models and Firmware VersionsYou can use remote management applications to install or upgrade ESXi, or to manage hosts remotely. Recommendations for Enhanced ESXi PerformanceTo enhance performance, install or upgrade ESXi on a robust system with more RAM than the minimum required and with multiple physical disks. Incoming and Outgoing Firewall Ports for ESXi HostsThe vSphere Web Client and the VMware Host Client allow you to open and close firewall ports for each service or to allow traffic from selected IP addresses. Required Free Space for System LoggingIf you used Auto Deploy to install your ESXi 6.5 host, or if you set up a log directory separate from the default location in a scratch directory on the VMFS volume, you might need to change your current log size and rotation settings to ensure that enough space is available for system logging . VMware Host Client System RequirementsMake sure that your browser supports the VMware Host Client. Parent topic: Upgrading ESXi Hosts