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JNCIS-ENT lab 8 of 17

Link aggregation and redundant trunk groups

Bundle the two links between the distribution switches into one LACP aggregate, so spanning tree stops blocking one of them, and make a dual-homed access switch fail over to its backup uplink in about a second: with a redundant trunk group on EX hardware, and with RSTP's alternate port on the virtual switches. Finish with how Virtual Chassis would change the design.

Run this lab

It needs Standard: its 3 nodes are set to 12 vCPU and 15,360 MB in total.

In your workspace: Shared, then JNCIS-ENT JN0-352 guided labs, then 08 - Link aggregation and redundant trunk groups

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 15,360 MB together. Every lab plan includes every guided lab.

Level
Advanced
Time
About 65 minutes
Nodes need
12 vCPU, 15,360 MB
Smallest plan
Standard

The scenario

Ashby Freight's distribution layer has two switches joined by two cables, and a dual-homed access switch below them. Today spanning tree does all the work: one of the two DIST links is blocked (wasting half the capacity), and ACCESS's backup uplink takes spanning-tree time to come up. You will:

  1. Bundle the two DIST1-DIST2 links into one aggregated Ethernet interface, ae0, with LACP.
  2. Make ACCESS's backup uplink take over in about a second. You will learn the redundant trunk group (RTG) that does this on EX switches, and test the same fail-over with RSTP's alternate port.

Each switch has an IRB address in VLAN DATA for testing (10.10.10.1, .2, .3).

What you’ll practise

  • Explain link aggregation, LACP modes and how traffic is spread across members
  • Configure an aggregated Ethernet interface with LACP and verify its members
  • Explain redundant trunk groups and their relationship with spanning tree
  • State the RTG configuration, and test uplink fail-over with an RSTP alternate port
  • Describe Virtual Chassis roles, mastership and its benefits

The tasks

  1. Today's topology
  2. Link aggregation with LACP
  3. Redundant uplinks: RTG, and the RSTP alternate port
  4. Virtual Chassis

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 Link aggregation and redundant trunk groups3 nodes, 4 links. Every link is listed as text below the diagram.DIST1DIST2ACCESSge-0/0/0ge-0/0/0ge-0/0/0ge-0/0/1ge-0/0/1ge-0/0/1ge-0/0/2ge-0/0/2
3 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • DIST1 ge-0/0/1 to DIST2 ge-0/0/1
  • DIST1 ge-0/0/2 to DIST2 ge-0/0/2
  • DIST1 ge-0/0/0 to ACCESS ge-0/0/0
  • DIST2 ge-0/0/0 to ACCESS ge-0/0/1
Nodes in Link aggregation and redundant trunk groups, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
DIST1Juniper vJunos-switchvjunosswitch-23.4R2-S2.14 vCPU, 5,120 MB
DIST2Juniper vJunos-switchvjunosswitch-23.4R2-S2.14 vCPU, 5,120 MB
ACCESSJuniper vJunos-switchvjunosswitch-23.4R2-S2.14 vCPU, 5,120 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 08 - Link aggregation and redundant trunk groups 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

All JNCIS-ENT labs

Related labs in other courses

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.