Before enabling jumbo frames, ensure the following are true:
- The physical server's network interface card and network switch can support jumbo frames (MTU 9000)
- The switch ports of all routers and switches between SoftNAS Cloud® and VMware vSphere hosts are properly configured for MTU 9000.
VMWare ESX/ESXi supports frames up to 9 Kb (MTU 9000).
In order to use jumbo frames support configuration is required end to end.
These commands are good for ESX/ESXi 5.0 and later:
- Log into host with the VMware vSphere client.
- Select the physical host to make changes to and click on the host IP.
- Choose the Configuration tab.
- Select the Networking option under Hardware.
- Select properties on the vSwitch to be configured.
When the vSwitch is selected, the MTU set will become visible under Advanced. - Set Properties. The default is 1500.
- Click Edit on the bottom while the vSwitch is selected.
- On the Generaltab there is a box labeled Advanced Properties
- Change the MTU here from 1500 to 9000 and click OK.
- Also change the MTU for the VMK (VM kernel).
In the same vSwitch Properties box select the first VMK listed. - The MAC address and MTU are listed under NIC Settings.
- Click Edit for the first VMK.
- On the properties dialogue box that pops up set the MTU in the NIC settings box on the General tab to 9000 and click OK.
- Repeat this for all VMKs under the virtual switch.
- Close the vSwitch properties dialogue and repeat for any remaining vSwitches.
Be sure to set the SoftNAS Cloud® network interface to accept Jumbo Frames / MTU 9000, as described above.