EVPNTypes

Posted on Oct 1, 2025

EVPN Route Types

Questions about the EVPN Route Types are pretty good interview questions for Network Engineers/ Architects. I keep forgetting the EVPN route types, so here is the EVPN route types explained so I can review them before an interview. I will separate them into their respective categories: “Standard” and “Multihoming”

Standard

  1. The bread and butter of EVPN, EVPN Route Type 2 is used to advertise the MAC address of a host. It can also be used to advertise a Mac & IP of a host. If a MAC+IP for a host is sent, it will send 2xType2’s ; 1 of Mac only, and 1 of Mac+IP. This is what allows for ARP Suppression and ARP Proxy in EVPN. Contains the following;

     	* MAC of Host/VM
 	* VNI of the vlan the host/mac was learnt on
 	* VTEP (Source VTEP who learnt this address)
 	* IP (as a /32 for host routes)
 	* Route Distinguisher
 	* Route Target

  2. EVPN Route Type 3 (also called ‘IMET’) is used to advertised membership of a specific Layer 2 domain (VNI). Leaf switches will send these to each other to build a dynmainc flood list, for the handling of BUM traffic. Route Type 3’s solve the “silent host” problem.

  3. Route Type 5’s advertise IP Prefixes and subnets. If you have a router attached to a border leaf, and redistribute routes learnt from it (i.e if you peer with it via OSPF), those learnt routes are advertised to other leafs as Type 5 Routes.

Multihoming/ Ethernet Segment

  1. Is used to announce the reachability of an Ethernet Segment, as well as fast convergence through the “mass withdraw” function. A mass withdraw is when you lose a device on the end of an Ethernet-Segment, and need to tell the rest of the network it’s gone. Typically, if you had 3 vlans on an Ethernet Segment (i.e 10,20,30) you would get a withdraw for each. A mass withdraw is sent as a bgp update, with a withdraw for all vlans.

  2. Specific to VTEP’s which have an active/active multihoming (Ethernet Segment) attached to them. This route is used to discover VTEP’s attached to the same Segment (i.e so they can find their buddies), and is also used for the Designated Forwarder election process. The DF process is used to ensure route-loop prevention.The “Route-target import” command under the port-channel config of the Ethernet segment is used to identify who will recieve the RT4 updates, and enables the election.