Andras Dosztal
Andras Dosztal
Network architect
Jul 20, 2021 2 min read

My First Arista VXLAN EVPN Fabric

thumbnail for this post

I put together my first Arista VXLAN EVPN fabric in GNS3. It is based on the Multi-Tenant EVPN VXLAN IRB Sample Configuration article @ Arista. Although there are some discrepancies (see below), it is still a very valuable source of information.

I also used the VXLAN Configuration blog post as well.

Changes to the Arista blog post

There are a few differences between my lab setup and the original artice:

  • I used symmetric IRB only and created all VNI’s on all leafs. In practice this allows VM mobility across the whole fabric.
  • 6 leafs are used instead of 4.
  • There were typos and incorrect values in the blog post, I corrected those.
  • The connected customer routers are IOU nodes.
  • Connected some “hosts” to leafs 3-6. These are also Arista switches where each SVI is in a separate VRF, acting like a host in its VLAN.

Please note that running this topology will take ~30-31 GB RAM.


Arista VXLAN EVPN fabric

Virtual cabling

I used the following cabling scheme:

  • The first ports are used to interconnect the fabric; i.e. it’s Ethernet1 to Ethernet6 on the spines, Ethernet1 to Ethernet4 on the leafs.
  • Ethernet5-6 are used for the MLAG peer link.
  • Ethernet10-11 are for downstream connections; peering external routers, ESXi hosts.

Config files

Configuration files can be downloaded from here.


Questions, comments? Raise it on my Facebook page.