Esx vmk is unable to pass traffic on VLAN (vlan tag set for Native and Trunk)

Products

• VMware vSphere ESXi

Issue/Introduction

• Native vlan is set the same as trunked vlan.
  
  
• Unable to pass traffic when setting the vlan tag.
  
  
• Traffic passes when set to no vlan tag.

Environment

vSphere ESX

Cause

When migrating an ESXi host's management interface (vmk0) from an access port (untagged) to a trunk port (tagged), a configuration mismatch can occur.

- If the physical switch port is changed to trunk mode before the ESXi Port Group is configured for Virtual Switch Tagging (VST), the host becomes isolated from the network and vCenter Server.

Resolution

• Confirm physical switchport settings for the vmnics backing vmk0 are configured for the appropriate VLAN Trunk range.
  
  
• If the host remains isolated, log in via the Direct Console User Interface (DCUI) and use Configure Management Network > VLAN (optional) to manually set the tag.

Additional Information

VLAN configuration on virtual switches, physical switches, and virtual machines.