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MikroTik MTCIPv6E lab 8 of 8

Capstone: troubleshooting a customer's IPv6 roll-out

A business customer's IPv6 roll-out has stalled: the router never gets a prefix, and when it does there's only room for one LAN, the PCs have addresses but no way out, and ping fails although the web works. Four faults are planted across the ISP's prefix delegation, the customer's firewall and its router advertisements. Find each one from its symptom, fix it, and finish numbering the office and guest LANs.

Run this lab

It needs Lite: its 4 nodes are set to 4 vCPU and 1,536 MB in total. That fits the free demo too.

In your workspace: Shared, then MikroTik MTCIPv6E RouterOS v7 guided labs, then 08 - Capstone - troubleshooting a customers IPv6 roll-out

Try it free for 30 minutesRun it on Lite from £3 a day

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Level
Advanced
Time
About 90 minutes
Nodes need
4 vCPU, 1,536 MB
Smallest plan
Lite

The scenario

A Fernvale business customer is rolling out IPv6. The design is the one from labs 2 to 4: the ISP delegates a /56 by DHCPv6; the customer router CPE numbers its office LAN (ether2) and guest LAN (ether3) with the first two /64s and advertises them; CPE's IPv6 firewall protects both. Somebody started the work and it stalled. The customer's ticket:

"The router never gets an IPv6 prefix. Your engineer says it's on your side. Also, the last time it did get one, the guest LAN had no IPv6, the PCs had addresses but no Internet, and ping didn't work even when browsing did."

There are four faults, on the ISP and on CPE. Find and fix them, finish numbering both LANs, and prove it from the PCs.

DeviceInterfaceNotes
ISPether1 · internetDHCPv6 server business, pool customers; Internet host 2001:db8:ffff::1
CPEether1 (WAN, link-local only) · ether2 (office) · ether3 (guest)DHCPv6 client into pool isp-pd
PC1 · PC2 (Linux)eth0SLAAC

What you’ll practise

  • Work from symptoms to causes across prefix delegation, router advertisements and the IPv6 firewall
  • Recognise a DHCPv6 client blocked by its own input chain
  • Spot a delegation that is too small for the customer's LANs
  • Explain why a zero router lifetime leaves hosts with addresses but no default route
  • Restore the ICMPv6 that IPv6 needs

The tasks

  1. "The router never gets a prefix"
  2. "The guest LAN had no IPv6"
  3. "Addresses but no Internet"
  4. "Ping doesn't work, browsing does"

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 Capstone - troubleshooting a customers IPv6 roll-out4 nodes, 3 links. Every link is listed as text below the diagram.ISPCPEPC1PC2ether1ether1ether2eth0ether3eth0
4 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • ISP ether1 to CPE ether1
  • CPE ether2 to PC1 eth0
  • CPE ether3 to PC2 eth0
Nodes in Capstone: troubleshooting a customer's IPv6 roll-out, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
ISPMikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB
CPEMikroTik RouterOSmikrotik-7.14.21 vCPU, 256 MB
PC1Alpine Linuxclbalpinebase-alpine-base-3-20-31 vCPU, 512 MB
PC2Alpine Linuxclbalpinebase-alpine-base-3-20-31 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 MikroTik MTCIPv6E RouterOS v7 guided labs.

  3. Open 08 - Capstone - troubleshooting a customers IPv6 roll-out 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.

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