STP Foundations and EtherChannel

40–50 min15 Questions

Skills Tested

Identify Layer 2 loop problems
Understand STP behavior and purpose
Identify root bridge and port roles
Interpret STP command output
Understand RSTP improvements
Configure and verify EtherChannel
Identify LACP vs PAgP behavior
Troubleshoot switching loops and link issues

Progress0%

A company added redundant links between switches for reliability.

Users report:

!Extremely slow network performance throughout the office
!Intermittent connectivity — devices dropping in and out
!Duplicate frames appearing on the network

Identify the issue, analyze STP behavior, ensure proper loop prevention, and implement EtherChannel correctly.

Network Topology

Redundant Switches

🔀Switch ARoot Candidate

🔀Switch BNon-Root

Loop Link

🔀Switch CNon-Root

STP active (forwarding)

STP blocked (loop prevention)

Multiple Choice

Q1/15

What is the main problem caused by Layer 2 loops in a switched network?

Progress0 correct

Q1Q15

Lessons Reinforced

Lesson 52: Layer 2 LoopsLesson 53: STP FundamentalsLesson 54: Root Bridge and Port RolesLesson 55: Rapid STPLesson 56: EtherChannel FundamentalsLesson 57: LACP and PAgP