All port groups on standard switches must be configured to a value other than that of the native virtual local area network (VLAN).
An XCCDF Rule
Description
<VulnDiscussion>ESXi does not use the concept of native VLAN. Frames with a VLAN specified in the port group will have a tag, but frames with VLAN not specified in the port group are not tagged and therefore will belong to the native VLAN of the physical switch. For example, frames on VLAN 1 from a Cisco physical switch will be untagged, because this is considered as the native VLAN. However, frames from ESXi specified as VLAN 1 will be tagged with a "1"; therefore, traffic from ESXi that is destined for the native VLAN will not be routed correctly (because it is tagged with a "1" instead of being untagged), and traffic from the physical switch coming from the native VLAN will not be visible (because it is not tagged). If the ESXi virtual switch port group uses the native VLAN ID, traffic from those virtual machines (VMs) will not be visible to the native VLAN on the switch because the switch is expecting untagged traffic.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-256424r886053_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
From the vSphere Client, go to Hosts and Clusters.
Select the ESXi Host >> Configure >> Networking >> Virtual switches.
For each port group on a standard switch that is configured to a native VLAN, click the "..." button next to the port group.