Virtual switch tagging (VST) allows greater flexibility when configuring
virtual networking, and is the most commonly used form of VLAN tagging. This SearchNetworking configuration guide offers tips and advice on how to configure your switch for
virtual switch tagging.
“Virtual switch tagging allows greater flexibility when configuring virtual networking because a few physical NICs can support a large number of VLANs. Not only can it simplify your virtual networking, it can also help reduce costs by limiting the number of physical NICs that a host needs to connect to many VLANs. Using VST is a must in any environment where the physical network topology is configured into many VLANs.
“Setting up your vSwitch to use VST mode is fairly simple. First, you need to configure the physical switch ports that the physical NICs of the vSwitch will be connected to. You will need to specify that the ports be configured as trunk ports and also configure the VLAN IDs that it will support. The configuration for this will vary based on the switch manufacturer. VMware provides a guide for 802.1Q VLAN solutions, with examples for Cisco switches. Once you have this configured, your pNICs in vSphere will start showing IP ranges for observed traffic in every VLAN for a specified configured port, as shown below.”