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Lab setup

As always, this tutorial will be backed up by a lab that readers can effortlessly deploy on their machine and follow along. Oper-group lab is contained within srl-labs/oper-group-lab repository and features:

  1. A Clos based fabric with 4 leaves and 2 spines, forming the fabric
  2. Two dual-homed clients emulated with linux containers and running iperf software to generate traffic
  3. L2 EVPN service1 configured across the leaves of the fabric
  4. A telemetry stack to demonstrate oper-group operations in action.

Physical topology#

On a physical layer topology interconnections are layed down as follows:

Each client is dual-homed to corresponding leaves; To achieve that, interfaces eth1 and eth2 are formed into a bond0 interface.
On the leaves side, the access interface `Ethernet-1/1`` is part of a LAG interface that is "stretched" between a pair of leaves, forming a logical construct similar to MC-LAG.

Fabric underlay#

In the underlay of a fabric leaves and spines run eBGP protocol to enable leaves to exchange reachability information for their system0 interfaces.

eBGP peerings are formed between each leaf and spine pair.

Fabric overlay#

To support BGP EVPN service, in the overlay iBGP peerings with EVPN address family are established from each leaf to each spine, with spines acting as route reflectors.

From the EVPN service standpoint, the mac-vrf instance named vrf-1 is created on leaves and ES-1 ethernet segment is formed from a LAG interface.

Ethernet segments are configured to be in an all-active mode to make sure that every access link is utilized in the fabric.

Telemetry stack#

We have enhanced the lab with a telemetry stack featuring gnmic, prometheus, and grafana - our famous GPG stack. Nothing beats real-time visualization, especially when we want to correlate events happening in the network.

Element Address
Grafana https://localhost:3000
Prometheus https://localhost:9090

Lab deployment#

Start with cloning lab's repository

git clone https://github.com/srl-labs/opergroup-lab.git && cd opergroup-lab

Lab repository contains startup configuration files for the fabric nodes, as well as necessary files for the telemetry stack to come up online operational. To deploy the lab:

containerlab deploy -t opergroup.clab.yml

This will stand up a lab with an already pre-configured fabric using startup configs contained within configs directory.

The deployed lab starts up in a pre-provisioned step, where underlay/overlay configuration has already been done. We proceed with oper-group use case exploration in the next chapter of this tutorial.


  1. Check L2 EVPN tutorial to get the basics of L2 EVPN service configuration. 

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