Vlan on vSwitch portgroup is not passing traffic through the network

Products

• VMware vSphere ESXi

Issue/Introduction

- You have a specific VLAN configured on a portgroup attached to the ESXi host.

- Vlan is tagged on that vSwitch port group 

- But the physical switch side where the ports connect to the Host uplinks, have the following configuration and the VLAN traffic is still not passing through:

switchport mode trunk
switchport trunk native vlan X

- VLAN is tagged on that network which is a Native VLAN

Environment

VMware vSphere ESXi

 

Cause

Native VLANs do not tag the out going VLAN packets toward ESX NICs and if the same VLAN ID is used to configure the vSwitch port group, the vSwitch drops any packet that is not tagged for it, causing the connection to fail.

Resolution

To resolve this issue:

- Remove the VLAN ID on the ESXi's vSwitch port group

 

Additional Information

Reference KB: Configuration of virtual switch VLAN tagging (VST Mode)