Configuring Flow Control on VMware ESXi and VMware ESX
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Configuring Flow Control on VMware ESXi and VMware ESX


Article ID: 324551


Updated On:


VMware vSphere ESXi


This article provides methods for disabling flow control on physical network interfaces used by an ESXi/ESX host.

Pause Frames are related to Ethernet flow control and are used to manage the pacing of data transmission on a network segment. Sometimes, a sending node (ESXi/ESX host, switch, and so on) may transmit data faster than another node can accept it. In this case, the overwhelmed network node can send pause frames back to the sender, pausing the transmission of traffic for a brief period of time.

If flow control is undesired in an environment, the support for flow control can be disabled for a given network interface or driver on the ESX/ESXi hosts. The method differs for different drivers.


VMware ESXi 4.0.x Embedded
VMware vSphere ESXi 5.1
VMware vSphere ESXi 5.0
VMware ESXi 3.5.x Installable
VMware vSphere ESXi 5.5
VMware ESXi 4.1.x Installable
VMware ESX 4.0.x
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 6.0
VMware ESX Server 3.5.x
VMware vSphere ESXi 6.5
VMware vSphere ESXi 6.7
VMware vSphere ESXi 7.0.0
VMware ESX 4.1.x
VMware ESX Server 3.0.x
VMware ESXi 4.0.x Installable
VMware ESXi 3.5.x Embedded


Configuring flow control using driver module options

ESXi 6.5/6.7/7.0 

  • List pause parameters of all NICs

    #esxcli network nic pauseParams list

  • Set pause parameters for a NIC

    #esxcli network nic pauseParams set

Cmd options:
-a|--auto=<bool> Enable/disable auto negotiation.
-n|--nic-name=<str> Name of NIC whose pause parameters should be set. (required)
-r|--rx=<bool> Enable/disable pause RX flow control.
-t|--tx=<bool> Enable/disable pause TX flow control.

​​​​​​​Note: A best practice is to check the current value of a parameter setting before and after making any change. Some network drivers provide module options which configure flow control functionality within the driver. Module options take effect during startup and, therefore, a reboot of the ESX/ESXi host is required. For more information on how to determine the available module options and to set a option, see Configuring advanced driver module parameters in ESX/ESXi (1017588).

Additional Information

Note: Not all network drivers and NICs allow flow control to be modified or used. For example, the e1000e driver does not support flow control. Use this command to view the parameters for a particular driver:
esxcli system module parameters list --module driver_name
You can filter the results with a grep command to get the value of a specific parameter:

esxcli system module parameters list --module e1000 | grep "FlowControl" .

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By default, flow control is enabled on all network interfaces in VMware ESXi and ESX. This is the preferred configuration in 1GB networks. If there are large numbers of pause frames in an environment, it is usually indicative of an underlying issue that should be investigated.