You can add or modify a virtual machine port group from the vSphere Client.

The vSphere Client Add Network wizard guides you through the tasks to create a virtual network to which virtual machines can connect, including creating a vSphere standard switch and configuring settings for a network label.

When you set up virtual machine networks, consider whether you want to migrate the virtual machines in the network between hosts. If so, be sure that both hosts are in the same broadcast domain—that is, the same Layer 2 subnet.

ESXidoes not support virtual machine migration between hosts in different broadcast domains because the migrated virtual machine might require systems and resources that it would no longer have access to in the new network. Even if your network configuration is set up as a high-availability environment or includes intelligent switches that can resolve the virtual machine’s needs across different networks, you might experience lag times as the Address Resolution Protocol (ARP) table updates and resumes network traffic for the virtual machines.

Virtual machines reach physical networks through uplink adapters. A vSphere standard switch can transfer data to external networks only when one or more network adapters are attached to it. When two or more adapters are attached to a single standard switch, they are transparently teamed.