STP 4: Port Priority Tie-Break on Parallel Links
Guide Rapid-PVST+ to prefer a specific parallel trunk by tuning the sender’s port priority on the root bridge. Two ioll2-xe switches (SW1, SW2) form a physical loop via two equal-speed trunks. A third L2 switch (SW3) extends the user VLAN to a second closet. One Alpine host attaches to SW1 and another to SW3 in VLAN 40 (10.1.40.0/24). You will: force SW1 to be the root for VLAN 40, lower the port priority on SW1’s Gi0/2 (Ethernet0/1) to break the tie so SW2 selects its Gi0/2 as the Root Port, enable PortFast and BPDU Guard on host-facing ports, and verify with show spanning-tree outputs and host pings.