STP Edge Port: Missing BPDU Guard
PortFast improves endpoint startup, but it must be paired with protections appropriate for an edge port. This lab distinguishes safe edge treatment from accidental switch-to-switch links.
The problem
A user-facing access port is enabled for PortFast without BPDU Guard. A small unmanaged switch is connected, creating a path that could introduce an unintended Layer 2 loop.
What you'll practice
- Read STP port roles and edge state
- Explain PortFast
- Apply BPDU Guard to an edge port
- Verify protective state
The topology
An access switch has user ports and one uplink; the fault is isolated to a user-facing edge port.
Commands to run yourself
The real diagnostic commands for this lab, copy-paste ready. Run these in the same order to reproduce the investigation on your own session.
show spanning-tree interface Ethernet1/0 detailshow running-config interface Ethernet1/0Topology diagram
Frequently asked
Is this aligned to CCNA practice?
Yes. It focuses on configuration, verification, and troubleshooting skills covered by the CCNA-level technology domain named on this lab.
Ready to run this lab yourself?
No setup, no image sourcing. Book a session or ask for a live demo.