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Arista EOS lab 10 of 20

VXLAN and EVPN with an MLAG leaf pair

Dual-home an access switch to an MLAG leaf pair that acts as one VTEP: shared VTEP loopback, iBGP underlay between the peers, EVPN to the spine, anycast gateways with the MLAG system MAC, and a failover test that keeps traffic flowing.

Run this lab

It needs Standard: its 7 nodes are set to 7 vCPU and 11,264 MB in total.

In your workspace: Shared, then Arista EOS guided labs, then 10 - VXLAN and EVPN with an MLAG leaf pair

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 7 vCPU and 11,264 MB together. Every lab plan includes every guided lab.

Level
Advanced
Time
About 90 minutes
Nodes need
7 vCPU, 11,264 MB
Smallest plan
Standard

The scenario

Northwind's web servers must survive a leaf failure, so rack 1 now has an MLAG pair, leaf1a and leaf1b, with the web access switch acc1 dual-homed to both. The pair's MLAG domain (POD1) and its eBGP sessions to spine1 are already up. Rack 2's leaf2 is a fully configured EVPN leaf hosting the database (VLAN 20, VRF TENANT-A, from lab 9), and VLAN 10 is already stretched to it for the web tier's future rack-2 servers. Your job is to make the MLAG pair a single EVPN VTEP, so the web tier in rack 1 reaches the database in rack 2 and keeps working when either rack-1 leaf fails. (One spine keeps the lab within the Standard plan; production would use two or more.)

DeviceLoopback0Loopback1 (VTEP)ASNotes
spine110.255.0.1–65000route server for EVPN
leaf1a10.255.0.1110.255.1.11 (shared)65001Vlan4094 10.255.255.1/30 · Vlan4093 10.255.254.1/30
leaf1b10.255.0.1210.255.1.11 (shared)65001Vlan4094 10.255.255.2/30 · Vlan4093 10.255.254.2/30
leaf210.255.0.1310.255.1.1365002VLAN 20 DB, gateway 10.20.20.1; VLAN 10 WEB is stretched here too (anycast gateway 10.10.10.1, no hosts yet)
h1–––on acc1 Et3, VLAN 10, 10.10.10.11/24 via 10.10.10.1
h2–––on leaf2 Et3, VLAN 20, 10.20.20.12/24 via 10.20.20.1

Overlay values: VLAN 10 ↔ VNI 10010, RT 10:10010, RD <Loopback0>:10010; VRF TENANT-A ↔ VNI 50001, RT 50001:50001, RD <Loopback0>:50001; anycast MAC 00:1c:73:00:00:99.

What you’ll practise

  • Dual-home a downstream switch to an MLAG pair with an MLAG port-channel
  • Give both MLAG peers the same VTEP address so the pair is one VTEP to the rest of the fabric
  • Add an iBGP underlay session between the peers with next-hop-self, and explain why it's needed
  • Use the MLAG system ID as the VXLAN router MAC for routed traffic
  • Verify with show vxlan config-sanity and from a remote leaf's view of the pair
  • Compare MLAG dual-homing with EVPN all-active multihoming (ESI, route types 1 and 4)

The tasks

  1. Dual-home acc1
  2. iBGP between the MLAG peers
  3. One VTEP for two switches
  4. EVPN overlay and tenant on the pair
  5. Test, then fail a leaf link

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 VXLAN and EVPN with an MLAG leaf pair7 nodes, 9 links. Every link is listed as text below the diagram.spine1leaf1aleaf1bleaf2acc1h1h2Ethernet3eth0Ethernet2Ethernet1Ethernet3eth0Ethernet4Ethernet1Ethernet4Ethernet2Ethernet2Ethernet2Ethernet3Ethernet3Ethernet1Ethernet1Ethernet3Ethernet1
7 nodes, with the interface names each link uses. On a narrow screen, scroll the diagram sideways.
Every link, as text
  • spine1 Ethernet1 to leaf1a Ethernet1
  • spine1 Ethernet2 to leaf1b Ethernet1
  • spine1 Ethernet3 to leaf2 Ethernet1
  • leaf1a Ethernet2 to leaf1b Ethernet2
  • leaf1a Ethernet3 to leaf1b Ethernet3
  • leaf1a Ethernet4 to acc1 Ethernet1
  • leaf1b Ethernet4 to acc1 Ethernet2
  • acc1 Ethernet3 to h1 eth0
  • leaf2 Ethernet3 to h2 eth0
Nodes in VXLAN and EVPN with an MLAG leaf pair, with the image each runs and the vCPU and RAM it’s set to
NodeDeviceImage in Add NodeSet to
spine1Arista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
leaf1aArista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
leaf1bArista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
leaf2Arista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
acc1Arista vEOSveos-4.33.1.1F1 vCPU, 2,048 MB
h1Alpine Linuxclbalpinebase-alpine-base-3-20-31 vCPU, 512 MB
h2Alpine 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 Arista EOS guided labs.

  3. Open 10 - VXLAN and EVPN with an MLAG leaf pair 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 Arista Networks. The lab follows exam topics and isn’t vendor training material; vendor names identify the exams and the images in the workspace.