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Cisco NX-OS data centre lab 14 of 15

Troubleshooting a VXLAN EVPN fabric

Tenant traffic has stopped on a two-leaf EVPN fabric. Work from the underlay up through BGP and the overlay to the tenant's L3 VNI, and clear four faults that each hide the next.

Run this lab

It needs Standard: its 6 nodes are set to 8 vCPU and 14,336 MB in total.

In your workspace: Shared, then Cisco Nexus NX-OS data centre guided labs, then 14 - Troubleshooting a VXLAN EVPN fabric

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 8 vCPU and 14,336 MB together. Every lab plan includes every guided lab.

Level
Advanced
Time
About 80 minutes
Nodes need
8 vCPU, 14,336 MB
Smallest plan
Standard

The scenario

Calder Freight's fabric from lab 8 has been rebuilt from a template by a contractor, and now H1 can't reach H2 or H3. R1 and the hosts are correct, so the faults are on N1 and N2. This is the design:

ItemValue
UnderlayOSPF area 0 on Ethernet1/1 and loopback0 of both leaves, through R1
OverlayiBGP AS 65000 between loopbacks 10.255.0.1 and 10.255.0.2, address family l2vpn evpn, extended communities on
VLAN 10VNI 10010 on both leaves, anycast gateway 10.10.10.1, route targets auto
VLAN 500L3 VNI 50001 for VRF RED on both leaves
VLAN 20N2 only, 10.20.20.0/24, gateway .1
HostsH1 10.10.10.11 on N1, H2 10.10.10.12 and H3 10.20.20.13 on N2

The goal: H1 reaches H2 (bridged) and H3 (routed).

What you’ll practise

  • Test the underlay before you read the overlay
  • Find why EVPN routes aren't imported
  • Find a VLAN-to-VNI mismatch
  • Tell L2 VNI faults from L3 VNI faults using show nve vni and the VRF routing table

The tasks

  1. Start the lab
  2. Start with the underlay
  3. The session's up, but no tunnel forms
  4. H1 still can't reach H2
  5. H1 can't reach H3

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 Troubleshooting a VXLAN EVPN fabric6 nodes, 5 links. Every link is listed as text below the diagram.N1N2R1H1H2H3e6eth0e6eth0e7eth0e1Gi0/0e1Gi0/1
6 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • N1 e1 to R1 Gi0/0
  • N2 e1 to R1 Gi0/1
  • N1 e6 to H1 eth0
  • N2 e6 to H2 eth0
  • N2 e7 to H3 eth0
Nodes in Troubleshooting a VXLAN EVPN fabric, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
N1Cisco Nexus 9000vnxosv9k-9300v-9.3.102 vCPU, 6,144 MB
N2Cisco Nexus 9000vnxosv9k-9300v-9.3.102 vCPU, 6,144 MB
R1Cisco IOSvvios-adventerprisek9-m.SPA.159-3.M61 vCPU, 512 MB
H1Alpine Linuxclbalpinebase-alpine-base-3-20-31 vCPU, 512 MB
H2Alpine Linuxclbalpinebase-alpine-base-3-20-31 vCPU, 512 MB
H3Alpine 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 Cisco Nexus NX-OS data centre guided labs.

  3. Open 14 - Troubleshooting a VXLAN EVPN fabric 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 Cisco. The lab follows exam topics and isn’t vendor training material; vendor names identify the exams and the images in the workspace.