What is the default setting for the MAC address changes in virtual switches?

The default setting for MAC address changes in virtual switches is to reject any such changes. This means that if a virtual machine attempts to change its MAC address, the virtual switch will not allow it, thus ensuring network security and stability. This is crucial because allowing changes to MAC addresses can lead to network issues, such as MAC flooding, and might be exploited for malicious activities like impersonating other devices on the network.

When MAC address changes are rejected, the virtual switch maintains the original MAC address assigned to the virtual machine, contributing to a stable and predictable networking environment. This feature is particularly important in multi-tenant environments where different virtual machines share the same physical network infrastructure.

The rejection of MAC address changes helps in maintaining integrity and preventing potential security breaches, which is why it is the default configuration in vSphere environments.