vSphere Distributed Switch Part 14 – Configuring dvPortGroup General Settings

Distributed Port Group (dvPortGroup) represents a group of dvPorts which shares the same configuration template. Applied configuration will be inherited from the dvPortGroup to the dvPorts. Port Group policies can be overridden on Per-dvport level. In vSphere standard switch, We will apply policy at vSwitch level and port Group level but on distributed switch, We will apply networking policies at dvPortGroup Level or at dvport level. In this post, I am going to explain you about how to configure Distributed Port Group General settings.

General Settings which are configured as part of Distributed port group includes portgroup name, Port binding options, Port allocation, Number of ports for the dvportgroup ,network resource pool and along with a description.

Under dvPortGroup General Settings, Enter the Name for dvPortGroup if you want to change it, Specify Number of Ports for this dvPortGroup and Description.Let’s understand Port binding and Port allocation policy in detail.

Below are the 3 different Port binding options available as part of dvportgroup general settings

1. Static Binding
2. Dynamic Binding
3. Ephemeral -no binding

Static Port Binding with Fixed Port allocation

Static Binding : This is the default port binding option. It assigns a  port to a virtual machine when a VM is connected to distributed port group. It assigns a port to connected virtual machines regardless of whether the connected virtual machines are powered up or not. It is not possible to connect any new virtual machines on the port group, If all the ports are booked by existing virtual machines.

For example:  if the total number of ports on my dvportGroup(Production) is 20. You can attach 20 virtual machines to this port group (PortGroup) regardless whether VM’s are powered on or off. If you try to connect a new virtual machines as 21st VM, It will not allow the VM to attach to the portgroup. Let’s prove this in the below scenario.

I have a Port group called “DPortGroup” with Static Binding as Port binding option and Fixed as my Port allocation Policy. I have configured Number of Ports as “3”.

When i am trying to connect my 4th Virtual machine to the PortGroup “DPortGroup”, I am getting the below error Message:

“No Free Port is available in Distributed Port Group”

Static Port Binding with Elastic Port allocation

If all the ports are occupied by connected virtual machines, vDS will automatically expand the port allocation pool to accommodate the required number of dvport. If the port is no longer needed (in case VM’s removed from the port group or VM deleted), ports will be reduced down to the numbers which was set at the time of creation.

Dynamic Port Binding

The Dynamic port binding type is deprecated. and it is no longer recommended. It is strongly recommended to choose the static port binding type for better performance. So I am not going to discuss about dynamic port binding policy.

Ephemeral-No Binding

Ephemeral binding behaves same as the standard vSwitch. If you have configured your dvPortgroup with ephemeral port binding then number of ports will be set to 0. Portgroup will allocate one port for each powered on virtual machine connected to that virtual machine upto the maximum number of ports available in the switch. If you choose your Port Binding as Ephemeral-No binding then, option to set number of ports will disappear.

In the below scenario, I have a dvport Group called “DportGroup” which is configured with Ephemeral port binding and I have connected 4  powered off virtual machines to this port group. Even 4 VM’s are connected but still Used Port is showing as “0” because VM’s are not powered on.

Once I powered on 3 virtual machines, It allocates the one port for each virtual machines with the Port ID.