CloudLabBox
Try the free demo

JNCIS-SP lab 12 of 16

GRE tunnels

Join two offices over a network that won't route their addresses, with a GRE tunnel, run OSPF through it, and find the tunnel's MTU limit.

Run this lab

It needs Lite: its 3 nodes are set to 5 vCPU and 7,680 MB in total. That fits the free demo too.

In your workspace: Shared, then JNCIS-SP JN0-364 guided labs, then 12 - GRE tunnels

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

The scenario

A small customer has offices in Malton and York, and only an internet connection at each. The router INTERNET stands for the internet: it routes the public link addresses and has no route to anything private. Skerry will join the offices with a GRE tunnel, and run the customer's routing over it.

DeviceInterfaceAddressNotes
R1ge-0/0/0198.51.100.2/30Default route to INTERNET
R1ge-0/0/1, lo010.1.0.1/24, 10.255.0.1/32Malton LAN
INTERNETGi0/0 / Gi0/1198.51.100.1/30 / 198.51.100.5/30Knows nothing about 10.0.0.0/8
R3ge-0/0/0198.51.100.6/30Default route to INTERNET
R3ge-0/0/1, lo010.3.0.1/24, 10.255.0.3/32York LAN
TunnelR1R3
gr-0/0/0.010.99.0.1/3010.99.0.2/30

What you’ll practise

  • Explain what tunnels are for and what they cost
  • Build a gr- interface and route into it
  • Run OSPF over GRE and avoid recursive routing
  • Measure the effect of GRE on the MTU

The tasks

  1. Why a tunnel, and the underlay
  2. Build the GRE tunnel
  3. OSPF over the tunnel
  4. MTU

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 GRE tunnels3 nodes and 2 networks, 4 links. Every link is listed as text below the diagram.R1INTERNETR3MaltonLANYorkLANge-0/0/1ge-0/0/1ge-0/0/0Gi0/0Gi0/1ge-0/0/0
3 nodes and 2 networks, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • R1 ge-0/0/1 to MaltonLAN (network)
  • R1 ge-0/0/0 to INTERNET Gi0/0
  • INTERNET Gi0/1 to R3 ge-0/0/0
  • R3 ge-0/0/1 to YorkLAN (network)
Nodes in GRE tunnels, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
R1Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 MB
INTERNETCisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
R3Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 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-SP JN0-364 guided labs.

  3. Open 12 - GRE tunnels 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-SP labs

All JNCIS-SP labs

Related labs in other courses

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.