CloudLabBox
Try the free demo

CCNP ENARSI lab 9 of 35

Troubleshooting OSPF

Six OSPF faults hide in a three-area network: stuck adjacencies, missing neighbours, a link that is FULL but unused, an isolated area and a missing external route. Diagnose each one from the evidence and fix it at the root.

Run this lab

It needs Lite: its 5 nodes are set to 5 vCPU and 2,560 MB in total. That fits the free demo too.

In your workspace: Shared, then CCNP ENARSI 300-410 guided labs, then 09 - Troubleshooting OSPF

Try it free for 30 minutesRun it on Lite from £3 a day

The free demo needs no card and no email. Every lab plan includes every guided lab.

Level
Advanced
Time
About 80 minutes
Nodes need
5 vCPU, 2,560 MB
Smallest plan
Lite

The scenario

Corvid Manufacturing's OSPF network was "tidied up" by a contractor who has since left. The design document is clear: area 0 is the triangle R1–R2–R3 with every link point-to-point and default timers and MTU; the office router R4 is in area 34; the factory router R5 is in area 25, an NSSA, and redistributes the partner extranet 172.31.99.0/24 into OSPF. Monday's tickets:

  1. "The R1–R2 adjacency never finishes; R2 is stuck in EXSTART or EXCHANGE."
  2. "R1 and R3 have never become neighbours."
  3. "Traffic from R2 to the office (10.4.4.0/24) goes round through R1 instead of over the direct R2–R3 link."
  4. "The office router R4 is isolated."
  5. "The factory router R5 has no OSPF neighbours."
  6. "HQ still can't reach the partner extranet 172.31.99.0/24, even though R5 is configured to redistribute it."
DeviceInterfaceAddressArea
R1Gi0/0 / Gi0/1 / Lo110.0.12.1 / 10.0.13.1 / 10.1.1.1 /240
R2Gi0/0 / Gi0/110.0.12.2 / 10.0.23.2 /240
R2Gi0/210.0.25.2/2425 (NSSA)
R3Gi0/0 / Gi0/110.0.13.3 / 10.0.23.3 /240
R3Gi0/210.0.34.3/2434
R4Gi0/0 / Lo110.0.34.4/24 / 10.4.4.1/2434
R5Gi0/0 / Lo110.0.25.5/24 / 10.5.5.1/2425
R5Lo99172.31.99.1/24external
R*n*Lo010.255.0.n/32router's area

What you’ll practise

  • Interpret neighbour states (INIT, 2WAY, EXSTART, EXCHANGE, FULL) to locate the fault
  • Diagnose MTU, timer, area ID and NSSA/stub flag mismatches
  • Recognise a network-type mismatch that leaves an adjacency FULL but unusable
  • Fix redistribution whose route map matches the wrong interface

The tasks

  1. Read the neighbour states
  2. Fix the adjacency problems (tickets 1, 2, 4 and 5)
  3. Fix the path problem (ticket 3)
  4. Fix the missing external route (ticket 6)
  5. Prove it

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 Troubleshooting OSPF5 nodes, 5 links. Every link is listed as text below the diagram.R1R2R3R4R5Gi0/2Gi0/0Gi0/2Gi0/0Gi0/0Gi0/0Gi0/1Gi0/0Gi0/1Gi0/1
5 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • R1 Gi0/0 to R2 Gi0/0
  • R1 Gi0/1 to R3 Gi0/0
  • R2 Gi0/1 to R3 Gi0/1
  • R3 Gi0/2 to R4 Gi0/0
  • R2 Gi0/2 to R5 Gi0/0
Nodes in Troubleshooting OSPF, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
R1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R2Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R3Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R4Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R5Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 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 CCNP ENARSI 300-410 guided labs.

  3. Open 09 - Troubleshooting OSPF 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 CCNP ENARSI labs

All CCNP ENARSI labs

Related labs in other courses

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