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Is the era of true open networking in data centers upon us?
Mar 1, 2015

Wide area networks and enterprise networks have benefitted from open standards based products for years. Products that adhere to open standard allow customers to choose best of breed products for each function with assurance that these products will work together. This open innovation has helped the industry to advance at a rapid pace.


Similarly, as data centers continue to grow and become the platforms for all cloud based services, standards based scalable technologies are required to architect these data centers. Some of the very large data centers recognized that early on and have been using protocols like BGP to build massively scalable data centers. However, in many enterprise data centers, since applications rely on the underlying topology, architecting a data center as an entirely L3 based data center is not always feasible. New standards are emerging that not only provide customers to take advantage of the scale offered by protocols like BGP, but also host legacy applications by providing a layer 2 service between any points within a data center and across data centers.


EVPN to the rescue:


Over last couple of years, the networking industry has rallied around Ethernet Virtual Private Network (EVPN) protocol to deliver an end to end solution – encompassing data center networks as well as WAN networks, providing a seamless end to end connectivity, from an application server in one data center to a database server in the same or different data center to a user consuming that data on a corporate network on his or her mobile phone. Juniper, Cisco, Alcatel-Lucent, AT&T, Verizon, Bloomberg and other participants have been helping define Ethernet VPN (EVPN), a new standards-based protocol for these interconnections.


One of the biggest advantage of EVPN is that it enables a wide variety of deployment options.


  1. EVPN leverages MPLS based forwarding plane in MPLS networks – ideally suited for WAN deployments as well as deployments in MPLS enabled data centers.
  2. EVPN leverages VXLAN based forwarding plane – ideally suited for data centers with IP fabric but equally suitable for WAN deployments where a customer needs to enable VPN service over plain IP infrastructure.
  3. Implementing EVPN with VXLAN in data centers with VTEP tunnels starting/ending in virtual routers (vRouters) allows L2 stretch functionality to VMs directly from server infrastructure.

The following diagram shows the flexibility of EVPN where it can be used inside data center with VXLAN and connecting multiple data centers using MPLS.




Additionally, combining best concepts of VPLS and well as IP-VPN technologies, EVPN overcomes the shortcoming of current data center switching and L2 WAN technologies such VPLS and L2VPNs. EVPN offers:


  • Integrated L2/L3 connectivity – pure L2, IP, IP-VPN – all connectivity options supported day one.
  • Native support for multi-homing.
  • Native support for MAC mobility, while avoiding traffic tromboning during MAC moves
  • Decreases or altogether eliminates the unknown unicast flooding; and mass MAC flush in the event of link failure.
  • Automatic discovery and propagation of routes to relevant switches for plug and play BGP deployment; and supports for advanced BGP based policies for finer control over service.
  • Built in network resiliency to protect against a variety of network failures.
  • It builds on widely deployed VPLS and IP-VPNs technologies, protecting investments in MPLS infrastructure and knowledge base.

Change of hearts and minds?


Technology industry is rife with examples of great technologies that have not been adopted for many non-technical reasons, so just the technical merits of EVPN are not enough to ensure widespread adoption. However, over the last couple of weeks we are seeing significant changes in industry adoption.


Cisco has recently chosen to enable EVPN on its Nexus 9000 product line, opening up interworking opportunities with other vendors. Juniper welcomes that Cisco has embraced open standard approach and we look forward to interoperate with Nexus as well as other product-lines in a multi-vendor interop and deployments. Standards based multi-vendor technologies such as EVPN put the choice squarely in customer’s hands to solve all their data connectivity needs with a promise of openness, scalability and interoperability instead of a single vendor forcing a proprietary and vertically integrated solution that may compromise performance, interoperability or both.


Talking about multi-vendor interop, over last two weeks, Cisco, Alcatel-Lucent and Juniper successfully completed first EVPN interop with VXLAN data plane. While it has taken the industry more than 3 years to perform first interop, it’s a step in the right direction. Juniper is looking forward to more interop events in upcoming conferences. Juniper has developed the EVPN technology broadly across its portfolio on EX, QFX and MX product lines.




Combination of technical benefits and improved adoption by all major vendors will bring forward the era of open standards networking in the data center and data center interconnects. With robust BGP / EVPN implementation on all platforms – QFX, EX, and MX, Juniper is uniquely positioned to bring EVPN technology to its full potential of providing optimized, seamless, and most importantly standards compliant L2 or L3 connectivity within data centers as well as across data centers.


Please see the following whitepaper for complete primer and value proposition of EVPN technology: