Deployment Guide

Static VXLAN VXLAN BGP EVPN
Data packets learn remote hosts after decapsulation of the VXLAN
header in the data plane.
Remote host MAC addresses are learned in the control plane using
BGP EVPN Type 2 routes and MAC/IP advertisements.
VXLAN BGP EVPN operation
The EVPN address family allows VXLAN to carry EVPN routes in External Border Gateway Protocol (eBGP) and Internal Border Gateway
Protocol (iBGP) sessions. In a data center network, use eBGP or iBGP for route exchange in both the IP underlay network and EVPN.
The following sample BGP EVPN topology shows a leaf-spine data center network where eBGP exchanges IP routes in the IP underlay
network, and exchanges EVPN routes in the VXLAN overlay network. All spine nodes are in one autonomous system—AS 65535. All leaf
nodes are in another autonomous system—AS 65000.
To advertise underlay IP routes, eBGP peer sessions establish between the leaf and spine nodes using an interface IP address. To
advertise EVPN routes, eBGP peer sessions between the leaf and spine nodes use a Loopback IP address.
Figure 3. BGP EVPN topology
Leaf nodes
Leaf nodes are typically top-of-rack (ToR) switches in a data center network. They act as the VXLAN tunnel endpoints and perform
VXLAN encapsulation and decapsulation. Leaf nodes also participate in the MP-BGP EVPN to support control plane and data plane
functions.
Control plane functions include:
• Initiate and maintain route adjacencies using any routing protocol in the underlay network.
• Advertise locally learned routes to all MP-BGP EVPN peers.
• Process the routes received from remote MP-BGP EVPN peers and install them in the local forwarding plane.
BGP EVPN for VXLAN
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