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JNCIS-ENT lab 16 of 17

Switching troubleshooting

Two floor switches were reconfigured over the weekend and five tickets are open. Work from the symptoms to six faults in VLAN membership, trunks, native VLANs, IRB interfaces and ports, using the switching show commands and pings from the PCs.

Run this lab

It needs Standard: its 6 nodes are set to 12 vCPU and 14,336 MB in total.

In your workspace: Shared, then JNCIS-ENT JN0-352 guided labs, then 16 - Switching troubleshooting

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 12 vCPU and 14,336 MB together. Every lab plan includes every guided lab.

Level
Advanced
Time
About 60 minutes
Nodes need
12 vCPU, 14,336 MB
Smallest plan
Standard

The scenario

Ashby Freight's two floor switches were "tidied up" over the weekend. Five tickets came in on Monday. The network contains six faults in the switch configurations; the PCs are correct.

The design

VLANIDSubnetGateway (SW1)Ports
STAFF1010.10.10.0/24irb.10 10.10.10.1SW1 ge-0/0/1 (PC1), SW2 ge-0/0/1 (PC3)
GUEST2010.20.20.0/24irb.20 10.20.20.1SW1 ge-0/0/2 (PC2), SW2 ge-0/0/2 (PC4)
MGMT9910.99.99.0/24SW1 irb.99 .1, SW2 irb.99 .2Native (untagged) on the trunk

The trunk ge-0/0/0 between the switches carries STAFF, GUEST and MGMT, with MGMT as the native VLAN on both ends. SW1 routes between STAFF and GUEST.

The tickets

  1. "PC1 can't reach anything, not even its gateway."
  2. "PC3 is offline."
  3. "PC4 can't reach its gateway."
  4. "Guest PCs can't reach the staff network (PC2 to PC1)."
  5. "We can't reach SW2's management address from SW1."

What you’ll practise

  • Troubleshoot Layer 2 reachability from the access port, through the trunk, to the gateway
  • Find VLAN membership, trunk member and native VLAN mismatches
  • Find IRB problems: wrong addresses and missing l3-interface bindings
  • Prove the repaired network against its design

The tasks

  1. Ticket 1: PC1
  2. Ticket 2: PC3
  3. Ticket 3: PC4
  4. Ticket 4: guests to staff
  5. Ticket 5: management

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 Switching troubleshooting6 nodes, 5 links. Every link is listed as text below the diagram.SW1SW2PC1PC2PC3PC4ge-0/0/2eth0ge-0/0/1eth0ge-0/0/1eth0ge-0/0/2eth0ge-0/0/0ge-0/0/0
6 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • SW1 ge-0/0/0 to SW2 ge-0/0/0
  • SW1 ge-0/0/1 to PC1 eth0
  • SW1 ge-0/0/2 to PC2 eth0
  • SW2 ge-0/0/1 to PC3 eth0
  • SW2 ge-0/0/2 to PC4 eth0
Nodes in Switching troubleshooting, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
SW1Juniper vJunos-switchvjunosswitch-23.4R2-S2.14 vCPU, 5,120 MB
SW2Juniper vJunos-switchvjunosswitch-23.4R2-S2.14 vCPU, 5,120 MB
PC1VPCS hostBuilt in to EVE-NGCounted as 1 vCPU, 1,024 MB
PC2VPCS hostBuilt in to EVE-NGCounted as 1 vCPU, 1,024 MB
PC3VPCS hostBuilt in to EVE-NGCounted as 1 vCPU, 1,024 MB
PC4VPCS hostBuilt in to EVE-NGCounted as 1 vCPU, 1,024 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 JNCIS-ENT JN0-352 guided labs.

  3. Open 16 - Switching troubleshooting 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 JNCIS-ENT labs

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