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Cisco NX-OS data centre lab 10 of 15

EEM applets and the scheduler

Make N1 look after itself. Embedded Event Manager applets block a dangerous command and bring up a standby uplink the moment the primary fails, and the scheduler saves the configuration on a timer.

Run this lab

It needs Lite: its 4 nodes are set to 5 vCPU and 7,680 MB in total. That fits the free demo too.

In your workspace: Shared, then Cisco Nexus NX-OS data centre guided labs, then 10 - EEM applets and the scheduler

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

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Level
Intermediate
Time
About 60 minutes
Nodes need
5 vCPU, 7,680 MB
Smallest plan
Lite

The scenario

Hall 3 pays for its standby line by the gigabyte, so Ethernet1/2 stays shut unless the primary line fails. There's nobody on site at night, so N1 has to do that by itself. Someone also typed write erase on the wrong switch last month, and the manager wants that made impossible. Finally, the night shift wants a fresh copy of the configuration kept on the switch every minute during the migration.

ItemValue
Primary uplinkEthernet1/1 to R1, 10.1.1.0/30, up
Standby uplinkEthernet1/2 to R2, 10.1.2.0/30, shut down
Carrier's service address203.0.113.1, on both R1 and R2
H110.10.10.11/24, gateway .1
OSPFArea 0 is already running on N1, R1 and R2

What you’ll practise

  • Write an EEM applet that matches a CLI command and overrides it
  • Use a track object to trigger an applet and change the configuration
  • Follow an applet through its history
  • Create scheduler jobs and schedules, and read their log

The tasks

  1. Start the lab
  2. Block a command
  3. React to a failure
  4. Fail the primary
  5. The scheduler

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 EEM applets and the scheduler4 nodes, 3 links. Every link is listed as text below the diagram.N1R1R2H1e5eth0e1Gi0/0e2Gi0/0
4 nodes, with the interface names each link uses.
Every link, as text
  • N1 e1 to R1 Gi0/0
  • N1 e2 to R2 Gi0/0
  • N1 e5 to H1 eth0
Nodes in EEM applets and the scheduler, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
N1Cisco Nexus 9000vnxosv9k-9300v-9.3.102 vCPU, 6,144 MB
R1Cisco IOSvvios-adventerprisek9-m.SPA.159-3.M61 vCPU, 512 MB
R2Cisco IOSvvios-adventerprisek9-m.SPA.159-3.M61 vCPU, 512 MB
H1Alpine 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 Cisco Nexus NX-OS data centre guided labs.

  3. Open 10 - EEM applets and the scheduler 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 Cisco NX-OS data centre labs

All Cisco NX-OS data centre labs

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.