Jumbo frames allow ESXi to send larger frames out onto the physical network. The network must support jumbo frames end-to-end. Jumbo frames up to 9kB (9000 bytes) are supported. Before enabling Jumbo frames, check with your hardware vendor to ensure that your physical network adapter supports jumbo frames.
Enable Jumbo Frames for a VMkernel Interface on a vSphere Standard Switch
Jumbo frames reduce the CPU load caused by transferring data. Enable jumbo frames on a VMkernel network interface by changing the maximum transmission units (MTU) of the VMkernel interface.
1. Log in to the vSphere Client and select the Hosts and Clusters inventory view.
2. On the host Configuration tab, click Networking.
3. Click Properties for the vSphere standard switch associated with the VMkernel to modify.
4. On the Ports tab, select the VMkernel interface and click Edit.
5. Set the MTU to 9000, and click OK.
Enable Jumbo Frames on a vSphere Distributed Switch
Enable a vSphere distributed switch for jumbo frames by changing the MTU size for that distributed switch.
1. Log in to the vSphere Client and select the Networking inventory view.
2. Right-click the vSphere distributed switch in the inventory pane, and select Edit Settings.
3. On the Properties tab, select Advanced.
4. Set the Maximum MTU to the largest MTU size among all the virtual network adapters connected to the vSphere distributed switch, and click OK.