AdvancedUnlock
Root Guard on Designated Ports
Advanced Rapid-PVST+ and Root Guard implementation on a three-switch triangle with a real loop. SW1 is the intentional root for VLAN 90 and protects its designated ports with Root Guard to prevent root re-parenting. Two Alpine hosts on VLAN 90 verify end-to-end forwarding remains stable even if a superior BPDU appears downstream.