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JNCIP-ENT lab 8 of 19

IGMP and PIM sparse mode

Carry a real multicast stream across three Junos routers: join with IGMP, build a shared tree to an RP, find the register tunnel's MTU limit, follow the switch to the source tree, and replace the static RP with BSR.

Run this lab

It needs Professional: its 6 nodes are set to 15 vCPU and 18,432 MB in total.

In your workspace: Shared, then JNCIP-ENT JN0-650 guided labs, then 08 - IGMP and PIM sparse mode

Run it on Professional from £7.50 a day

The free demo can’t run it: it has 6 vCPU and 8 GB, and this lab’s nodes need 15 vCPU and 18,432 MB together. Every lab plan includes every guided lab.

Level
Advanced
Time
About 90 minutes
Nodes need
15 vCPU, 18,432 MB
Smallest plan
Professional

The scenario

Northmere's training team wants to stream video from one server to every depot, and sending a copy to each viewer would swamp the WAN. You'll turn on IP multicast across three routers. H1 is the video server, and H2 and H3 are viewers. The traffic is real: iperf sends UDP to a group and the hosts receive it. So you'll see not just the protocol state but the packets arrive, or fail to.

DeviceInterfaceAddressLink
R1ge-0/0/0, ge-0/0/110.0.12.1/30, 10.0.13.1/30To R2, to R3
R1ge-0/0/2, lo010.1.1.1/24, 10.255.0.1/32H1's LAN
R2ge-0/0/0, ge-0/0/110.0.12.2/30, 10.0.23.1/30To R1, to R3
R2ge-0/0/2, lo010.2.2.1/24, 10.255.0.2/32H2's LAN
R3ge-0/0/0, ge-0/0/110.0.13.2/30, 10.0.23.2/30To R1, to R2
R3ge-0/0/2, lo010.3.3.1/24, 10.255.0.3/32H3's LAN
H1, H2, H3eth010.1.1.10, 10.2.2.10, 10.3.3.10Gateway is .1 on each LAN

OSPF already runs on all three routers. Each router has tunnel-services turned on, which is what gives it the interfaces PIM needs for registering sources. There's no multicast configuration yet.

What you’ll practise

  • Explain multicast addressing and IGMP
  • Configure PIM sparse mode and an RP on Junos
  • Trace a source through registering and the SPT switchover
  • Use the RPF check to explain a tree
  • Discover an RP with BSR

The tasks

  1. Join a group with IGMP
  2. Build a shared tree with PIM sparse mode
  3. Send data, and find the register MTU
  4. Follow the tree from RP to source
  5. Replace the static RP with BSR

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 IGMP and PIM sparse mode6 nodes, 6 links. Every link is listed as text below the diagram.R1R2R3H1H2H3ge-0/0/2eth0ge-0/0/2eth0ge-0/0/2eth0ge-0/0/1ge-0/0/1ge-0/0/0ge-0/0/0ge-0/0/1ge-0/0/0
6 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • R1 ge-0/0/0 to R2 ge-0/0/0
  • R1 ge-0/0/1 to R3 ge-0/0/0
  • R2 ge-0/0/1 to R3 ge-0/0/1
  • R1 ge-0/0/2 to H1 eth0
  • R2 ge-0/0/2 to H2 eth0
  • R3 ge-0/0/2 to H3 eth0
Nodes in IGMP and PIM sparse mode, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
R1Juniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
R2Juniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
R3Juniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
H1EVE-NG GUI server (Docker)eve-gui-server:latest1 vCPU, 1,024 MB
H2EVE-NG GUI server (Docker)eve-gui-server:latest1 vCPU, 1,024 MB
H3EVE-NG GUI server (Docker)eve-gui-server:latest1 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 JNCIP-ENT JN0-650 guided labs.

  3. Open 08 - IGMP and PIM sparse mode 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 JNCIP-ENT labs

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