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

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

This article describes the various VLAN tagging methods used with ESXi/ESX.

Virtual LAN (VLAN) implementation is recommended in ESXi/ESX networking environments because:

• It integrates ESXi/ESX into a pre-existing network
• It secures network traffic
• It reduces network traffic congestion
• iSCSI traffic requires an isolated network

Environment

VMware vCenter Server 
VMware vSphere ESXi

Resolution

Video tutorial for various VLAN tagging methods used with ESXi/ESX:

VLAN tagging methods used with ESXi/ESX:

There are three methods of VLAN tagging that can be configured on ESXi/ESX:

• External Switch Tagging (EST)
• Virtual Switch Tagging (VST)
• Virtual Guest Tagging (VGT)

External Switch Tagging (EST)

• All VLAN tagging of packets is performed on the physical switch.
• ESXi/ESX host network adapters are connected to access ports on the physical switch.
• The portgroups connected to the virtual switch must have their VLAN ID set to 0.
• For more information, see Sample Configuration - ESXi/ESX connecting to physical switch via VLAN access mode and External Switch VLAN Tagging (EST Mode)
• See this example snippet of a code from a Cisco switch port configuration:
  
  switchport mode access
switchport access vlan x

Virtual Switch Tagging (VST)

• All VLAN tagging of packets is performed by the virtual switch before leaving the ESXi/ESX host.
• The ESXi/ESX host network adapters must be connected to trunk ports on the physical switch.
• The portgroups connected to the virtual switch must have an appropriate VLAN ID specified.
• For more information, see:
  • Configuring a VLAN on a portgroup
  • Configuring Virtual Switch VLAN Tagging (VST) mode on a vNetwork Distributed Switch
• For a sample of VST, see Sample configuration of virtual switch VLAN tagging (VST Mode)
• See this example snippet of code from a Cisco switch port configuration:
  
  switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan x,y,z
spanning-tree portfast trunk

Note: The Native VLAN is not tagged and thus requires no VLAN ID to be set on the ESXi/ESX portgroup.

Virtual Guest Tagging (VGT)

• All VLAN tagging is performed by the virtual machine.
• You must install an 802.1Q VLAN trunking driver inside the virtual machine.
• VLAN tags are preserved between the virtual machine networking stack and external switch when frames are passed to/from virtual switches.
• Physical switch ports are set to trunk port.
• For more information, see Sample configuration of virtual machine (VM) VLAN Tagging (VGT Mode) in ESX
• See this example snippet of code from a Cisco switch port configuration:
  
  switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk allowed vlan x,y,z
spanning-tree portfast trunk

Additional Information

• VMware Skyline Health Diagnostics for vSphere - FAQ
• Sample configuration of virtual switch VLAN tagging (VST Mode)
• Sample Configuration - ESX/ESXi connecting to physical switch via VLAN access mode and External Switch VLAN Tagging (EST Mode)
• Sample configuration of virtual machine VLAN Tagging (VGT Mode) in ESX
• Configuring Virtual Switch VLAN Tagging (VST) mode on a vNetwork Distributed Switch
• Configuring a VLAN on a portgroup
• Troubleshooting: ESXi hosts have intermittent or no network connectivity
• Troubleshooting virtual machine network connection issues

For translated versions of this article, see:

• 虚拟交换机、物理交换机及虚拟机上的 VLAN 配置
• 仮想スイッチ、物理スイッチおよび仮想マシン上の VLAN 構成