Redundancy: STP & EtherChannel

Covers Lesson 5 and Lesson 6

Checks the two answers to the same problem: STP blocks a redundant link to break a loop, and EtherChannel makes the loop disappear so nothing has to be blocked.

Topics covered

• Loops, broadcast storms, and why Ethernet has no TTL
• Root election, port roles, and path cost
• Rapid PVST+ states and per-VLAN trees
• LACP and PAgP modes, and the consistency requirements

Every question here is answerable from the first-party notes of the lessons above. You commit to an answer before you see whether it was right.

This quiz is a Week 3 milestone in its own right. Passing it does not change the completion state of any individual lesson, and you do not need it to finish the lessons it covers.

Section quiz

Redundancy: STP & EtherChannel

8 questions covering Lesson 5 and Lesson 6. Answer each one before you see whether you were right.

Question 1 of 8

1. Why does a Layer 2 loop produce a broadcast storm when an IP routing loop eventually stops itself?

2. How is the root bridge elected?

3. What role do the ports on the root bridge take?

4. What is the standard short-mode STP port cost for a 1 Gbps link?

5. Under Rapid PVST+, what is the non-forwarding state called, and where does that port sit?

6. Which LACP mode combination never forms a bundle?

7. Which statement about LACP and PAgP is correct?

8. show etherchannel summary shows one member as (P) and the other as (s). What does that tell you?

Back to Lesson 6 Continue to Lesson 7

Back to Week 3