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JNCIS-ENT lab 14 of 17

GRE and IP-IP tunnels

Connect HQ and a branch across a provider that only routes public addresses. You enable tunnel services, build a GRE tunnel and run OSPF through it for the office LANs, add an IP-IP tunnel for the camera network, and learn the tunnel's MTU, its recursive-routing trap and how to troubleshoot it.

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 14 - GRE and IP-IP tunnels

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 70 minutes
Nodes need
12 vCPU, 15,360 MB
Smallest plan
Standard

The scenario

Ashby Freight's new branch is connected to the internet through the same provider as HQ. The provider routes only the public link addresses (198.51.100.0/30 and 198.51.100.4/30) and drops everything addressed to private networks. You will build two tunnels between HQ and the branch, over the provider:

TunnelInterfaceHQBRANCHCarries
GREgr-0/0/0.010.255.0.1/3010.255.0.2/30The office LANs (10.1.0.0/24 and 10.9.0.0/24), routed by OSPF
IP-IPip-0/0/0.010.255.1.1/3010.255.1.2/30The camera networks (10.1.50.0/24 and 10.9.50.0/24), static routes

Tunnel endpoints are the routers' internet addresses: HQ 198.51.100.2, BRANCH 198.51.100.6. Both routers have a default route to the provider.

What you’ll practise

  • Explain why tunnels are used, and the overhead, MTU and routing considerations they bring
  • Enable tunnel services and create gr- and ip- interfaces
  • Configure a GRE tunnel and run OSPF across it
  • Configure an IP-IP tunnel and route through it with static routes
  • Avoid recursive routing of tunnel endpoints
  • Troubleshoot tunnels with interface, route, ping and traceroute output

The tasks

  1. Why a tunnel?
  2. Tunnel services
  3. The GRE tunnel
  4. OSPF through the tunnel
  5. The IP-IP tunnel for the cameras
  6. MTU inside the tunnel
  7. Troubleshoot a broken tunnel

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 and IP-IP tunnels3 nodes and 4 networks, 6 links. Every link is listed as text below the diagram.HQPROVIDERBRANCHHQ-LANHQ-CamerasBranch-LANBranch-Camerasge-0/0/2ge-0/0/2ge-0/0/3ge-0/0/3ge-0/0/0ge-0/0/0ge-0/0/0ge-0/0/1
3 nodes and 4 networks, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • HQ ge-0/0/0 to PROVIDER ge-0/0/0
  • BRANCH ge-0/0/0 to PROVIDER ge-0/0/1
  • HQ ge-0/0/2 to HQ-LAN (network)
  • HQ ge-0/0/3 to HQ-Cameras (network)
  • BRANCH ge-0/0/2 to Branch-LAN (network)
  • BRANCH ge-0/0/3 to Branch-Cameras (network)
Nodes in GRE and IP-IP tunnels, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
HQJuniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
PROVIDERJuniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
BRANCHJuniper vJunos-routervjunosrouter-24.2R1-S2.54 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 14 - GRE and IP-IP 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-ENT labs

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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.