Details

Certain physical switches reserve certain VLAN IDs for internal purposes and often disallow traffic configured to these values. For example, Cisco Catalyst switches typically reserve VLANs 1001-1024 and 4094, while Nexus switches typically reserve 3968-4047 and 4094. Check the documentation for the specific switch. Using a reserved VLAN might result in a denial of service on the network.

Solution

From the vSphere Client, select the ESXi host and go to Configure >> Networking >> Virtual switches.

Highlight a port group where VLAN ID is set to a reserved value and click ‘Edit’ settings (dots).

Change the VLAN ID to an appropriate VLAN and click ‘OK’.

or

From a PowerCLI command prompt while connected to the ESXi host, run the following command:

Get-VirtualPortGroup -Name ‘portgroup name’ | Set-VirtualPortGroup -VLanId ‘New VLAN#’

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-7_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system VMware.

References

• 800-53|CM-6b.
• CAT|II
• CCI|CCI-000366
• Rule-ID|SV-239319r674886_rule
• STIG-ID|ESXI-67-000065
• STIG-Legacy|SV-104163
• STIG-Legacy|V-94077
• Vuln-ID|V-239319

Source

• Tenable.com/audits