Network lab report

Rapid PVST+ in a Looped Layer 2 Topology

A Cisco campus-design lab covering root election, port roles, blocked paths, redundancy, and convergence.

Objective

Observe how Rapid PVST+ removes loops while preserving redundancy.

This CML campus-design lab stretches VLAN 10 across a redundant four-switch topology, configures Rapid PVST+, validates root-bridge election, and inspects forwarding versus alternate port roles.

Planned four-switch STP topology — Planned Layer 2 campus topology with dual-homed access switches and an inter-distribution link.

Running four-switch STP topology — Running CML topology used for Rapid PVST+ verification.

Observed forwarding tree

DIST1	Root bridge for VLAN 10; all participating ports designated and forwarding.
DIST2	Root port on the direct inter-distribution link toward DIST1.
SW1	Primary uplink forwarding; redundant uplink alternate and blocking.
SW2	Primary uplink forwarding; redundant uplink alternate and blocking.

SW1 spanning tree verification — SW1 verification output: one root forwarding port and one alternate blocking port.

DIST1 spanning tree verification — DIST1 verification output confirming root-bridge role for VLAN 10.

Operational interpretation

Physical redundancy does not guarantee simultaneous forwarding capacity in a Layer 2 design.
STP intentionally blocks selected links to create a loop-free tree.
Rapid PVST+ preserves alternate paths for failure recovery while preventing broadcast loops.
The result motivates comparison against routed-access and logical-switch campus designs.