Unable to increase the number of ports on a virtual switch in ESXi 5.5 (2064511)

Symptoms

• When you increase the number of ports on a vSwitch in an ESXi 5.5 host using the vSphere Client, the changes are not reflected on the host even after reboot
• The option to modify the number of ports does not exist in the vSphere Web Client
• When number of ports on a vSwitch is set to 2040 or 4088 using the vSphere Client, the client reports the error:
  
  A specified parameter was not correct
  Call "HostNetworkSystem.UpdateVirtualSwitch" for object "networkSystem-263" on vCenter Server "vCenter" failed.
  
• In the hostd.log file, located at /var/log, you see entries similar to:
  
  Throw vmodl.fault.InvalidArgument
  Formatfiled: Optional unset (vmodl.fault.InvalidArgument.invalidProperty)

Resolution

This is an expected behavior.

 

By design, the number of ports on a standard virtual switch in  ESXi 5.5 cannot be modified. To ensure efficient use of resources on hosts running ESXi 5.5, the ports of virtual switches are dynamically scaled up and down. A switch on such a host can expand up to the maximum number of ports supported on the host. The port limit is determined based on the maximum number of virtual machines that the host can handle. It uses only the elastic option and the ports are dynamically increased or reduced according to need. By functionality, it is similar to the auto-expand feature available in dvSwitch starting with vSphere 5.0.

 

However, the vSphere Client still shows 120 ports by default and allows you to modify, though the default is set to 1536 at the back-end and does not change.

The vSphere Web Client correctly shows the updated value for the number of ports as elastic.

Running the esxcli network vswitch standard list command from the shell prompt shows Num Ports as 1536.

Source:-

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2064511