What should the maximum bandwidth setting be for the VMs using an external virtual switch mapped to a 1 Gbps NIC?

The correct maximum bandwidth setting for virtual machines (VMs) using an external virtual switch mapped to a 1 Gbps Network Interface Card (NIC) is 1000 Mbps (or 1 Gbps). However, if the chosen answer was 250, it might refer to a scenario where the virtual switch is configured to limit the total bandwidth available to the VMs for various reasons, such as prioritizing network traffic or ensuring that no single VM monopolizes network resources.

It's important to consider that in practical implementations, inherent overhead and the need for network efficiency would often recommend configuring a setting that provides a buffer below the maximum capability of the NIC. Therefore, while the maximum theoretical bandwidth of the NIC is 1 Gbps, selecting lower values (such as 500 Mbps, 250 Mbps, or other varied configurations) can be strategic depending on the network traffic expectations and VM requirements.

In general, the best practice is not to exceed the physical capabilities of the network infrastructure while appropriately managing bandwidth to ensure smooth operations across all VMs. Thus, while the exact reasons for specific lower settings depend on the situation, the understanding of the maximum potential of a 1 Gbps NIC is crucial for correctly configuring VM settings in a virtualized environment.