You can add new hosts to a vSphere Distributed Switch, connect network adapters to the switch, and remove hosts from the switch. In a production environment, you might need to keep the network connectivity up for virtual machines and VMkernel services while you manage host networking on the distributed switch.
Adding Hosts to a vSphere Distributed Switch
Consider preparing your environment before you add new hosts to a distributed switch.
Create distributed port groups for virtual machine networking.
Create distributed port groups for VMkernel services. For example, create distributed port groups for management network, vMotion, and Fault Tolerance.
Configure enough uplinks on the distributed switch for all physical NICs that you want to connect to the switch. For example, if the hosts that you want to connect to the distributed switch have eight physical NICs each, configure eight uplinks on the distributed switch.
Make sure that the configuration of the distributed switch is prepared for services with specific networking requirements. For example, iSCSI has specific requirements for the teaming and failover configuration of the distributed port group where you connect the iSCSI VMkernel adapter.
You can use the Add and Manage Hosts wizard in the vSphere Web Client to add multiple hosts at a time.
Managing Network Adapters on a vSphere Distributed Switch
After you add hosts to a distributed switch, you can connect physical NICs to uplinks on the switch, configure virtual machine network adapters, and manage VMkernel networking.
If some hosts on a distributed switch are associated to other switches in your data center, you can migrate network adapters to or from the distributed switch.
If you migrate virtual machine network adapters or VMkernel adapters, make sure that the destination distributed port groups have at least one active uplink, and the uplink is connected to a physical NIC on the hosts. Another approach is to migrate physical NICs, virtual network adapters, and VMkernel adapters simultaneously.
If you migrate physical NICs, leave at least one active NIC that handles the traffic of port groups. For example, if vmnic0 and vmnic1 handle the traffic of the VM Network port group, migrate vmnic0 and leave vmnic1 connected to the group.
Removing Hosts from a vSphere Distributed Switch
Before you remove hosts from a distributed switch, you must migrate the network adapters that are in use to a different switch.
To add hosts to a different distributed switch, you can use the Add and Manage Hosts wizard to migrate the network adapters on the hosts to the new switch all together. You can then remove the hosts safely from their current distributed switch.
To migrate host networking to standard switches, you must migrate the network adapters in stages. For example, remove physical NICs on the hosts from the distributed switch by leaving one physical NIC on every host connected to the switch to keep the network connectivity up. Next, attach the physical NICs to the standard switches and migrate VMkernel adapters and virtual machine network adapters to the switches. Lastly, migrate the physical NIC that you left connected to the distributed switch to the standard switches.