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JNCIS-SP lab 10 of 16

Segment routing with IS-IS

Solve the BGP-free core problem a third way: with no label protocol, just a number for each router in IS-IS. See the same label on every hop, and no per-LSP state.

Run this lab

It needs Standard: its 6 nodes are set to 10 vCPU and 15,360 MB in total.

In your workspace: Shared, then JNCIS-SP JN0-364 guided labs, then 10 - Segment routing with IS-IS

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

Level
Advanced
Time
About 70 minutes
Nodes need
10 vCPU, 15,360 MB
Smallest plan
Standard

The scenario

Skerry's core routers P1 and P2 don't run BGP, because a core that doesn't carry customer routes needs far less memory and has far fewer reasons to fail. IS-IS runs everywhere, PE1 and PE2 are IBGP peers, and each has a customer. The BGP routes are in place, but CE1 can't reach CE2: PE1 sends plain IP packets to P1, and P1 has no route, so it drops them. You'll fix that with MPLS, without adding one customer route to the core.

DeviceInterfaceAddressNotes
PE1ge-0/0/0 / ge-0/0/110.0.12.1/30 / 10.0.14.1/30To P1, and direct to PE2 with IS-IS metric 100
PE1ge-0/0/2, lo0172.16.1.1/30, 10.255.0.1/32EBGP to CE1
P1ge-0/0/0 / ge-0/0/1, lo010.0.12.2/30 / 10.0.23.1/30, 10.255.0.2/32No BGP
P2ge-0/0/0 / ge-0/0/1, lo010.0.23.2/30 / 10.0.34.1/30, 10.255.0.3/32No BGP
PE2ge-0/0/0 / ge-0/0/110.0.34.2/30 / 10.0.14.2/30To P2, and direct to PE1 with IS-IS metric 100
PE2ge-0/0/2, lo0172.16.2.1/30, 10.255.0.4/32EBGP to CE2
CE1Gi0/0, Loopback1172.16.1.2/30, 192.168.1.1/24AS 65001
CE2Gi0/0, Loopback1172.16.2.2/30, 192.168.2.1/24AS 65002

What you’ll practise

  • Explain SIDs, the SRGB and why the core has no per-LSP state
  • Configure node SIDs in IS-IS
  • Read L-ISIS routes and the labels in mpls.0
  • Show how shortest-path SR LSPs follow the IGP

The tasks

  1. Segment routing in one statement
  2. Read the labels
  3. Carry the traffic
  4. Shortest paths and repairs

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 Segment routing with IS-IS6 nodes, 6 links. Every link is listed as text below the diagram.CE1PE1P1P2PE2CE2Gi0/0ge-0/0/2Gi0/0ge-0/0/2ge-0/0/0ge-0/0/0ge-0/0/1ge-0/0/0ge-0/0/1ge-0/0/0ge-0/0/1ge-0/0/1
6 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • PE1 ge-0/0/0 to P1 ge-0/0/0
  • P1 ge-0/0/1 to P2 ge-0/0/0
  • P2 ge-0/0/1 to PE2 ge-0/0/0
  • PE1 ge-0/0/1 to PE2 ge-0/0/1
  • CE1 Gi0/0 to PE1 ge-0/0/2
  • CE2 Gi0/0 to PE2 ge-0/0/2
Nodes in Segment routing with IS-IS, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
CE1Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 vCPU, 512 MB
PE1Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 MB
P1Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 MB
P2Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 MB
PE2Juniper vSRX NextGen templatevsrxng-24.4R1.92 vCPU, 3,584 MB
CE2Cisco IOSvvios-adventerprisek9-m.spa.159-3.m91 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 JNCIS-SP JN0-364 guided labs.

  3. Open 10 - Segment routing with IS-IS 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.