Explanation
BGP EVPN is a control plane protocol that can be used for VXLAN networks . VXLAN is a technology that creates overlay networks to extend Layer 2 connectivity across Layer 3 networks . BGP EVPN has the following functions as a VXLAN control plane protocol:
It automatically establishes the VXLAN tunnel between VTEPs (VXLAN Tunnel Endpoints), which are devices that encapsulate and decapsulate VXLAN packets . You do not need to manually configure a full-mesh tunnel between all VTEPs, which reduces the configuration complexity and improves the scalability .
It advertises host routes and MAC address entries on the control plane, which are used to learn the location of hosts and their corresponding VTEPs . This reduces the unknown traffic flooding that occurs when the destination MAC address is unknown, and optimizes the packet forwarding by using optimal paths .
It implements Layer 2 interconnection between data centers in different networking modes, such as bridging, routing, or integrated routing and bridging (IRB) . This enables seamless communication between hosts in different subnets or VLANs across data centers .
It advertises subnet routes to implement Layer 3 interconnection of data centers through VXLAN tunnels . This enables routing between different subnets or VLANs across data centers without requiring an external gateway device .