The vCenter Server must manage excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of denial-of-service (DoS) attacks by enabling Network I/O Control (NIOC).

DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.

Managing excess capacity ensures sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.

If distributed switches are not used, this is not applicable.

From the vSphere Client, go to Networking.

Select a distributed switch >> Configure >> Settings >> Properties.

View the "Properties" pane and verify "Network I/O Control" is "Enabled".

or

From a PowerCLI command prompt while connected to the vCenter server, run the following command:

Get-VDSwitch | select Name,@{N="NIOC Enabled";E={$_.ExtensionData.config.NetworkResourceManagementEnabled}}

If "Network I/O Control" is disabled, this is a finding.

From the vSphere Client, go to Networking.

Select a distributed switch >> Configure >> Settings >> Properties.

In the "Properties" pane, click "Edit". Change "Network I/O Control" to "Enabled". Click "OK".

or

From a PowerCLI command prompt while connected to the vCenter server, run the following command:

(Get-VDSwitch "VDSwitch Name" | Get-View).EnableNetworkResourceManagement($true)