Which configuration setting ensures that virtual networks on a virtual switch are isolated from each other?

The setting that ensures virtual networks on a virtual switch are isolated from each other is the VLAN ID. VLAN, or Virtual Local Area Network, is a network protocol that creates distinct, isolated subnetworks within a larger network. By assigning different VLAN IDs to the virtual networks connected through a virtual switch, network administrators can ensure that traffic from one VLAN cannot be seen or accessed by another VLAN. This operational isolation is essential for security and ensuring that various tenant environments do not interfere with one another.

Using VLAN IDs effectively allows for more efficient use of networking resources and provides better segregation for different business units or applications within the same physical infrastructure. Each virtual switch can manage multiple VLANs, with devices from different VLANs unable to communicate unless configured to do so through routing.

In contrast, other options like Port ID, Network Label, and Security Policy do not inherently provide the same level of network isolation as VLAN IDs. Port IDs are simply identifiers for the switch ports and do not dictate how traffic is managed between networks. Network Labels serve more for administrative purposes in identification than for enforcing isolation. Security Policies can provide additional restrictions and measures, but they do not create the foundational separation that VLAN IDs do.