CCNA: Spanning Tree Root Bridge

Three switches form a loop. STP elected SW1 as root just because it has the lowest MAC address. Make SW3 — the core switch — the root, and SW2 the backup.

Tasks

1. Run show spanning-tree on SW1, SW2 and SW3. Which switch is root, and which port is blocking (BLK)?
2. Make SW3 the root bridge for VLAN 1 with priority 4096.
3. Make SW2 the secondary root with priority 8192.
4. Verify SW3 now says "This bridge is the root" and its ports are all Designated/FWD.