Traditional stack management MAC address

The traditional stack is identified in the network by a single MAC address, usually the MAC address of the active controller (the default). If a new active controller is elected, the MAC address of the new active controller (by default) becomes the MAC address for the entire stack. However, you can manually configure your stack to use a specified MAC address.

In a traditional stack, the management MAC address is generated by the software and is always the MAC address of the first port of the active controller. This ensures that the management MAC address remains consistent across stack reboots and helps prevent frequent topology changes that result from protocol enable, disable, and configuration changes.

When you are configuring Layer 2 protocols, such as STP, RSTP, and MSTP, on stack units, the management MAC address of the active controller acts as the Bridge ID.