Deployment Guide

BGP EVPN for VXLAN
Ethernet Virtual Private Network (EVPN) is a control plane for VXLAN that reduces flooding in the network and resolves scalability
concerns. EVPN uses MP-BGP to exchange information between VTEPs. EVPN was introduced in RFC 7432 and is based on BGP MPLS-
based VPNs. RFC 8365 describes VXLAN-based EVPN.
The MP-BGP EVPN control plane provides protocol-based remote VTEP discovery, and MAC and ARP learning. This configuration
reduces flooding related to L2 unknown unicast traffic. The distribution of host MAC and IP reachability information supports virtual
machine (VM) mobility and scalable VXLAN overlay network designs.
The BGP EVPN protocol groups MAC addresses and ARP/neighbor addresses under EVPN instances (EVIs) to exchange them between
VTEPs. In OS10, each EVI is associated with a VXLAN VNI in 1:1 mapping.
Benefits of a BGP EVPN-based VXLAN
• Eliminates the flood-and-learn method of VTEP discovery by enabling control-plane learning of end-host L2 and L3 reachability
information.
• Minimizes network flooding of unknown unicast and broadcast traffic through EVPN-based MAC and IP route advertisements on local
VTEPs.
• Provides support for host mobility.
Topics:
• BGP EVPN compared to static VXLAN
• VXLAN BGP EVPN operation
• Configure BGP EVPN for VXLAN
• VXLAN BGP EVPN routing
• BGP EVPN with VLT
• VXLAN BGP commands
• VXLAN EVPN commands
• Example: VXLAN with BGP EVPN
• Example: VXLAN with BGP EVPN — Multi-AS Topology
• Example: Centralized Layer3 gateway routing
• Example: Border Leaf Gateway
BGP EVPN compared to static VXLAN
OS10 supports two types of VXLAN NVO overlay networks:
• Static VXLAN
• BGP EVPN
Configure and operate static VXLANs and BGP EVPNs for VXLAN in the same way:
• Manually configure the overlay and underlay networks.
• Manually configure each virtual network and VNI.
• Manually configure access port membership in a virtual network.
• Existing routing protocols provision and learn underlay reachability to VTEP peers.
However, static VXLANs and BGP EVPNs for VXLAN differ as described:
Table 6. Differences between Static VXLAN and VXLAN BGP EVPN
Static VXLAN VXLAN BGP EVPN
To start sending and receiving virtual-network traffic to and from a
remote VTEP, manually configure the VTEP as a member of the
virtual network.
No manual configuration is required. Each remote VTEP is
automatically learned as a member of a virtual network from the
EVPN routes received from the remote VTEP. After a remote
VTEP address is learned, VXLAN traffic is sent to, and received
from, the VTEP.
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