Cloud & Networking Consulting, Project Management

Ethernet VPN (EVPN) is a next generation solution that provides Ethernet multipoint services over MPLS networks.

EVPN operates in contrast to the existing Virtual Private LAN Service (VPLS) by enabling control-plane based MAC learning in the core. In EVPN, PE’s participating in the EVPN instances learn MAC routes in Control-Plane and IP addresses using MP-BGP protocol. Control-plane MAC learning brings a number of benefits that allow EVPN to address the VPLS shortcomings, including support for multi-homing with per-flow load balancing. The EVPN control-plane MAC learning has the following benefits: • Eliminate flood and learn mechanism. • MAC Mobility. • Fast-reroute, resiliency, and faster network convergence. • Enables load balancing of traffic to and from CEs that are multi-homed to multiple PEs. • Fast convergence to minimize downtime and packet loss.

The following table shows a comparison of some key points for EVPN/MPLS and VPLS:

Use MPLS Transport Yes Yes
Protocol Evolution (Design Life) Next Generation Legacy
MPLS Fast Reroute (FRR) < 50ms Yes Yes
L2 Stretching Yes Yes
L3 Routing Integration Yes, Integrated Routing andBridging (IRB). Single VPN technology for L3 and L2 VPNs. No
VLAN Design Flexible. Significant to the location. Flat VLANs extended across locations can impact performance.
High Exposure to Broadcast Storms No Yes
DoS Attack Probability Low High
L2 PDUs must be tunnelled across MPLS Core, such as Spanning Tree (STP) BPDUs No Yes
Broadcast, Unknown Unicast and Multicast (BUM) Traffic Suppression of BUM traffic at the PE device (locally). Multicast and broadcast radiation to all sites.
MAC Address Learning Control Plane (more efficient and scalable). Data Plane (scalability considerations/limitations).
BGP to advertise MAC/IP info Yes No
Multi homing Active-Active per Flow Yes No
Multi homing Active-Standby per VLAN/Service Yes Yes
MAC Mobility Yes No
MAC Mass-Withdraw for fast convergence BGP Based Withdraw. LDP/BGP Based Withdraw.
Seamless VM Mobility Yes No
QoS Support Yes Yes