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Aruba CX lab 4 of 16

MSTP design and loop protection

Replace the accidental spanning tree of a looped triangle with a designed MSTP region: two instances with roots on different distribution switches, edge ports with BPDU guard, root guard towards the access layer, and loop protect for unmanaged switches.

Run this lab

It needs Standard: its 4 nodes are set to 7 vCPU and 9,728 MB in total.

In your workspace: Shared, then HPE Aruba Networking CX switching guided labs, then 04 - MSTP design and loop protection

Run it on Standard from £5 a day

The free demo can’t run it: it has 6 vCPU and 8 GB, and this lab’s nodes need 7 vCPU and 9,728 MB together. Every lab plan includes every guided lab.

Level
Intermediate
Time
About 60 minutes
Nodes need
7 vCPU, 9,728 MB
Smallest plan
Standard

The scenario

Northwind's warehouse core is a triangle: dist1, dist2 and the access switch acc1, all trunking VLANs 10 and 20. Someone enabled spanning tree with defaults, so the loop is blocked, but the root is whichever switch has the lowest MAC address, and both VLANs use the same links. Your job: design MSTP so VLAN 10 prefers dist1 and VLAN 20 prefers dist2, make the edge safe, and stop the access layer from ever taking over the root.

LinkPorts
dist1 – dist21/1/1 – 1/1/1
dist1 – acc11/1/2 – 1/1/1
dist2 – acc11/1/2 – 1/1/2
acc1 – h101/1/3 (VLAN 10)

What you’ll practise

  • Read the default spanning tree and predict which port blocks
  • Configure an MST region (name, revision, VLAN-to-instance map) identically on three switches
  • Place each instance's root with priorities and verify per-instance port roles
  • Protect the edge with admin-edge ports, BPDU guard and loop protect
  • Protect the root with root guard

The tasks

  1. Read the accidental tree
  2. One region for everyone
  3. Place the roots
  4. Protect the edge
  5. Protect the root
  6. Test

The Lab Tasks pane has the scenario, these tasks, the checks to run, hints and the full solution.

Topology and devices

The network as it opens in EVE-NG, drawn from the lab’s own canvas, and the image each node runs.

Topology of MSTP design and loop protection4 nodes, 4 links. Every link is listed as text below the diagram.dist1dist2acc1h101/1/3eth01/1/21/1/11/1/21/1/21/1/11/1/1
4 nodes, with the interface names each link uses.
Every link, as text
  • dist1 1/1/1 to dist2 1/1/1
  • dist1 1/1/2 to acc1 1/1/1
  • dist2 1/1/2 to acc1 1/1/2
  • acc1 1/1/3 to h10 eth0
Nodes in MSTP design and loop protection, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
dist1Aruba AOS-CX virtual switcharubacx-10.142 vCPU, 3,072 MB
dist2Aruba AOS-CX virtual switcharubacx-10.142 vCPU, 3,072 MB
acc1Aruba AOS-CX virtual switcharubacx-10.142 vCPU, 3,072 MB
h10Alpine Linuxclbalpinebase-alpine-base-3-20-31 vCPU, 512 MB

How to open this lab

  1. Sign in to your workspace at lab.cloudlabbox.com.

  2. In File Manager, open Shared, then the folder HPE Aruba Networking CX switching guided labs.

  3. Open 04 - MSTP design and loop protection and start its nodes, then open Lab Tasks for the scenario and the steps.

The lab is read-only. You can start the nodes and configure the devices, but changes to the topology can’t be saved. To change it, rebuild it in your own folder.

More Aruba CX labs

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CloudLabBox is independent of Hewlett Packard Enterprise. The lab follows exam topics and isn’t vendor training material; vendor names identify the exams and the images in the workspace.