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The vCenter Server must not configure VLAN Trunking unless Virtual Guest Tagging (VGT) is required and authorized.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-258940VCSA-80-000273SV-258940r961863_ruleCCI-000366medium
Description
When a port group is set to VLAN Trunking, the vSwitch passes all network frames in the specified range to the attached virtual machines without modifying the virtual local area network (VLAN) tags. In vSphere, this is referred to as VGT. The virtual machine must process the VLAN information itself via an 802.1Q driver in the operating system. VLAN Trunking must only be implemented if the attached virtual machines have been specifically authorized and are capable of managing VLAN tags themselves. If VLAN Trunking is enabled inappropriately, it may cause a denial of service or allow a virtual machine to interact with traffic on an unauthorized VLAN.
STIGDate
VMware vSphere 8.0 vCenter Security Technical Implementation Guide2026-05-23

Related Frameworks

1 mapping across 5 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (8) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

CFG-01Configuration Management Program
1.00
END-01Endpoint Device Management (EDM)
1.00
END-04Malicious Code Protection (Anti-Malware)
1.00
END-06Endpoint File Integrity Monitoring (FIM)
1.00
MON-01Continuous Monitoring
1.00
MON-01.7File Integrity Monitoring (FIM)
1.00
CFG-02Secure Baseline Configurations
0.50
CFG-02.7Approved Configuration Deviations
0.50
NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (100) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-12Session Termination
1.00
AC-16(1)Dynamic Attribute Association
1.00
AC-17(1)Monitoring and Control
1.00
AC-2Account Management
1.00
AC-2(1)Automated System Account Management
1.00
AC-2(11)Usage Conditions
1.00
AC-2(3)Disable Accounts
1.00
AC-2(4)Automated Audit Actions
1.00
AC-24(1)Transmit Access Authorization Information
1.00
AC-25Reference Monitor
1.00

+90 more (top 10 by confidence shown)

NIST 800-1710 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (2) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

3.4.1
1.00
3.4.2
1.00
CCI1 mapping
CCI-000366
1.00
NIST CSF 2.00 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (5) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

DE.CM-09
1.00
PR.PS-01
1.00
PR.DS-10
0.50
PR.PSPlatform Security
0.50
PR.PS-05
0.50

Who does this work

10 NICE work roles and 9 EC-Council certifications.

This is an inference across published mappings, not a single claim by anyone. This check maps to a control, which maps to a Cybersecurity Framework outcome, which NIST assigns to the work roles below. EC-Council separately maps its certifications to those same roles.

A certification prepares someone for a role. It is not evidence that a holder is qualified, and neither NIST nor EC-Council has stated that any certification here addresses this check.

Work-role assignments published by NIST (NICE Framework Components 2.2.0 and the CSF 2.0 OLIR crosswalk). Certification mappings published by EC-Council.

Details

Check Text (C-258940r961863_chk)

If distributed switches are not used, this is not applicable. From the vSphere Client, go to "Networking". Select a distributed switch >> Select a distributed port group >> Configure >> Settings >> Policies. Review the port group "VLAN Type" and "VLAN trunk range", if present. or From a PowerCLI command prompt while connected to the vCenter server, run the following command: Get-VDPortgroup | Where {$_.ExtensionData.Config.Uplink -ne "True"} | Select Name,VlanConfiguration If any port group is configured with "VLAN trunking" and is not documented as a needed exception (such as NSX appliances), this is a finding. If any port group is authorized to be configured with "VLAN trunking" but is not configured with the most limited range necessary, this is a finding.

Fix Text (F-62589r934477_fix)

From the vSphere Client, go to "Networking". Select a distributed switch >> Select a distributed port group >> Configure >> Settings >> Policies. Click "Edit". Click the "VLAN" tab. If "VLAN trunking" is not authorized, remove it by setting "VLAN type" to "VLAN" and configure an appropriate VLAN ID. Click "OK". If "VLAN trunking" is authorized but the range is too broad, modify the range in the "VLAN trunk range" field to the minimum necessary and authorized range. An example range would be "1,3-5,8". Click "OK". or From a PowerCLI command prompt while connected to the vCenter server, run the following command to configure trunking: Get-VDPortgroup "Portgroup Name" | Set-VDVlanConfiguration -VlanTrunkRange "<VLAN Range(s) comma separated>" or Run this command to configure a single VLAN ID: Get-VDPortgroup "Portgroup Name" | Set-VDVlanConfiguration -VlanId "<New VLAN#>"