Introduction to EVPN Control Plane

Introduction to EVPN Control Plane

Are you looking for a reliable and secure way to manage your network? EVPN Control Plane can provide you with the control and flexibility you need to get the most out of your network. 

This powerful technology allows you to control who learns what, apply policies, and maintain the virtualization of EVPN instances.

EVPN Control Plane
Fig 1.1- EVPN Control Plane

💻 Table Of Content

1. What is EVPN?

EVPN (Ethernet Virtual Private Network), enables virtualized Ethernet communication between various network devices. Data center and service provider networks frequently employ EVPN to offer effective and scalable network connection.

EVPN provides several benefits over traditional Layer 2 VPN technologies, such as Virtual Private LAN Service (VPLS). One of the main benefits of EVPN is that it enables multi-tenancy, where multiple customers or tenants can share the same physical infrastructure while maintaining separate and secure virtual networks. 

EVPN also provides more efficient use of network resources and better scalability compared to traditional Layer 2 VPN technologies.

2. What is EVPN Control Plane?

EVPN Control Plane uses MP-BGP to advertise MAC addresses and IPs for next hop to other PEs over an EVPN NLRI. This provides load balancing over multiple LSPs between the same PEs, and also load balancing of traffic between CEs that are multihomed to a number of PEs. 

This helps to improve convergence time in the event of a CE-PE link failure. Even though MAC address learning over the MPLS core happens in the control plane, learning between PEs and CEs is done by the method preferred by the CE, such as data plane learning, 802.1aq, ARP, or other protocols.

Also read below:
Understanding EVPN Data Plane: The Basics

3. Using Control Plane for EVPN MAC Learning

EVPN traffic is kept separate and isolated by using the control plane to learn MAC addresses. This helps PEs advertise MAC addresses and IPs for next hop routes over MP-BGP with an EVPN NLRI. And it's not just for load balancing between the same PEs over multiple LSPs, but also for load balancing traffic between multiple PEs and CEs.

Plus, there's flexibility in how the PEs and CEs learn from each other. The CE can choose the method preferred by them, whether it's data plane learning, 802.1aq, ARP or something else. And the PE L2 forwarding table can include all the MAC addresses known to the control plane, just the MAC addresses of active flows, or even a cache-based scheme.

4. EVPN Policy Attributes

EVPN policy attributes are somewhat similar to those of L3VPN. Each EVI needs a unique RD assigned to each PE and one or more globally unique RTs. With these attributes, EVPN traffic is kept separated from other traffic and is easily managed.

By leveraging control plane learning, EVPN traffic is more secure, manageable and efficient. It's a powerful tool that helps keep networks running smoothly and keeps them secure.

5. Conclusion

EVPN uses two control plane protocols: the Border Gateway Protocol (BGP) and the Multi-Protocol Label Switching (MPLS) protocol. BGP is used for route distribution and advertisement, while MPLS is used for forwarding traffic.

The EVPN control plane offers several benefits, including efficient use of network resources, fast convergence times, and support for large-scale networks. Additionally, EVPN enables the deployment of new services and applications, such as network virtualization and data center interconnect.

Overall, EVPN is a powerful networking technology that provides a scalable and flexible solution for building virtual private networks over Ethernet infrastructure. Its control plane is a critical component that enables the efficient distribution of MAC address reachability information across the network, enabling fast and reliable forwarding of traffic.

Continue Reading...