CCIE 400-101: Layer 2 Technologies - Loop Guard, Root Guard on September 30, 2017 Spanning Tree Protocol STP +
CCIE 400-101: Layer 2 Technologies - PortFast, BPDU Guard, BPDU Filter on September 28, 2017 Spanning Tree Protocol STP +
Classic STP Convergence: Handling Direct and Indirect Link Failures on September 26, 2017 Spanning Tree Protocol STP +
CCIE 400-101: Layer 2 Technologies - Switch priority, port priority, path cost on September 11, 2017 Spanning Tree Protocol STP +