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Study CCNP

3.1 Layer 2

1 min read ENCOR 350-401 v1.2

Aligned to Cisco's 350-401 ENCOR v1.2 exam topics.

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Layer 2 questions are usually about one of three things:

  1. A VLAN is not crossing a link.
  2. Several physical links are not acting like one logical link.
  3. Spanning tree is blocking, protecting, or reconverging differently than expected.

The fix is rarely magic. Verify the control plane, verify the port state, then verify the data plane.

Study order

  1. 802.1Q trunking
  2. EtherChannels
  3. RSTP, MST, root guard, and BPDU guard

Objectives

  1. 3.1.a Troubleshoot static and dynamic 802.1q trunking protocols
  2. 3.1.b Troubleshoot static and dynamic EtherChannels
  3. 3.1.c Configure and verify common Spanning Tree Protocols (RSTP, MST) and Spanning Tree enhancements such as root guard and BPDU guard