All port groups must not be configured to VLAN values reserved by upstream physical switches.

From VMware vSphere vCenter Server Version 6 Security Technical Implementation Guide

Associated with: CCI-000366

SV-78467r1_rule All port groups must not be configured to VLAN values reserved by upstream physical switches.

Vulnerability discussion

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 with the documentation for your specific switch. Using a reserved VLAN might result in a denial of service on the network.

Check content

From the vSphere Web Client go to Networking >> Select a distributed port group >> Manage >> Settings >> Policies. Review the port group VLAN tags and verify they are not set to a reserved VLAN ID. or From a PowerCLI command prompt while connected to the vCenter server run the following command: Get-VDPortgroup | select Name, VlanConfiguration If any port group is configured with a reserved VLAN ID, this is a finding.

Fix text

From the vSphere Web Client go to Networking >> Select a distributed port group >> Manage >> Settings >> Policies. Click Edit and under the VLAN section change the VLAN ID to not be a reserved VLAN ID and click OK. or From a PowerCLI command prompt while connected to the vCenter server run the following command: Get-VDPortgroup "portgroup name" | Set-VDVlanConfiguration -VlanId "New VLAN#"

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.