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JNCIS-ENT lab 17 of 17

Routing capstone troubleshooting

The final routing exam: a dual-homed site with OSPF, IBGP between loopbacks, EBGP to a provider, export and import policy and a VRRP gateway, broken in six places that hide behind each other. Restore it to the design from five trouble tickets.

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 17 - Routing capstone troubleshooting

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

The scenario

Ashby Freight's dual-homed site was rebuilt during a weekend change. On Monday morning there are five tickets. The ISP router is correct and is not yours to change. The site contains six faults.

The design

ItemDesign
AS numbersAshby 65010, ISP 64500
IGPOSPF area 0 between EDGE1 and EDGE2 (ge-0/0/1, point-to-point), plus the user LAN and loopbacks as passive
IBGPBetween loopbacks 192.168.255.21 and 192.168.255.22, with local-address; each edge sends IBGP routes with next-hop self (policy NHS)
EBGPEDGE1 to 198.51.100.1, EDGE2 to 198.51.100.5, peer AS 64500, MD5 key Ashby-BGP-2026
OutboundBoth edges advertise only the aggregate 10.65.0.0/16 with community 65010:100; EDGE2 prepends 65010 65010
Exit pathEDGE1 sets local preference 200 on routes from the ISP, so all outbound traffic leaves through EDGE1
GatewayVRRP group 1, address 10.65.0.1: EDGE1 master (priority 200, pre-empts), EDGE2 backup (priority 100)

The tickets

  1. "EDGE1 has no BGP session to the ISP."
  2. "The IBGP session between the edge routers is down."
  3. "EDGE2 is sending its internet traffic out of the backup link."
  4. "The ISP sees our address block from only one router."
  5. "The VRRP master is the wrong router."

The test PC is the routing instance PC on EDGE2 (10.65.0.100, default route to 10.65.0.1): run its tests on EDGE2 with routing-instance PC.

What you’ll practise

  • Troubleshoot an IGP adjacency that BGP depends on
  • Diagnose IBGP and EBGP session failures from show bgp neighbor and the logs
  • Find missing next-hop self and export policy problems from the receive and advertising views
  • Diagnose a VRRP master that contradicts the design
  • Verify a repaired network against its design end to end

The tasks

  1. Ticket 1: EDGE1 and the ISP
  2. Ticket 2: IBGP
  3. Ticket 3: EDGE2 uses the backup link
  4. Ticket 4: only one router advertises the block
  5. Ticket 5: VRRP

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 Routing capstone troubleshooting3 nodes and 1 network, 6 links. Every link is listed as text below the diagram.EDGE1EDGE2ISPUser-LANge-0/0/2ge-0/0/2ge-0/0/3ge-0/0/0ge-0/0/0ge-0/0/0ge-0/0/1ge-0/0/1ge-0/0/1
3 nodes and 1 network, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • EDGE1 ge-0/0/0 to ISP ge-0/0/0
  • EDGE2 ge-0/0/0 to ISP ge-0/0/1
  • EDGE1 ge-0/0/1 to EDGE2 ge-0/0/1
  • EDGE1 ge-0/0/2 to User-LAN (network)
  • EDGE2 ge-0/0/2 to User-LAN (network)
  • EDGE2 ge-0/0/3 to User-LAN (network)
Nodes in Routing capstone troubleshooting, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
EDGE1Juniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
EDGE2Juniper vJunos-routervjunosrouter-24.2R1-S2.54 vCPU, 5,120 MB
ISPJuniper 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 17 - Routing capstone troubleshooting 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.