At the time of initial cluster build, you can choose the MTU size to assign to the virtual-distributed switches. Doing so enables you to configure the switch ports supporting the VxRail cluster to match the MTU setting on the virtual-distributed switches. It reduces the potential for network fragmentation.
You can choose to run the VxRail cluster at the default MTU size of 1500, or if your network supports it, choose a larger MTU. If your data center network supports jumbo frames, Dell Technologies recommends configuring the MTU size at 9000. A resource-intense network such as vSAN is better suited for a network that is configured with jumbo frames.