Posting this blog on behalf of Babi Seal, Senior Manager, Product Management, INSBU, who has been driving  BGP EVPN based solutions in the datacenter.

Digital disruptors have challenged established business models by creating new ways of engaging with customers in real-time to better serve the changing customer needs. To maximize revenue and maintain customer interest, businesses must transform.

Cisco has been innovating all aspects of IT, enabling customers to move faster, handle ever-increasing traffic loads, and deliver the applications and services needed to grow and be competitive. Cisco’s Nexus 9000 family of switches provides key innovations and sets the stage for the new era of digital transformation. Some of these innovations include:

  • Cloudscale ASICs
  • ACI for policy and automation
  • Tetration for visibility and security
  • Control plane enhancements with BGP/EVPN
  • Common orchestration plane and fabric OAM for management and serviceability

EVPN with Cisco Nexus 9000 continues to mature

This month Cisco is noting the two-year anniversary of our launch of the BGP EVPN Control Plane for VXLAN on the Nexus 9000 family of switches. The BGP EVPN control plane is designed to address multi-tenancy, scalability and workload mobility requirements for modern data centers. The Nexus 9000 was the first switch in the market to support VXLAN routing, thereby enabling customers to push out their L2/L3 boundaries to the access layer in the datacenter. By employing the EVPN control plane to distribute reachability information and realizing a distributed IP Anycast Gateway, optimal layer 2 and layer 3 forwarding is achieved by disaggregating the necessary forwarding state.

Customer Adoption success 

Since our launch, more than 100 Cisco customers in the enterprise and service provider space have deployed the VXLAN EVPN solution; some in very large fabrics comprising hundreds of switches. This market traction is important as VXLAN is the de-facto standard for overlays in the industry. Cisco has focused on developing BGP EVPN as the control plane for VXLAN by co-authoring and driving multiple IETF drafts toward standardization. As we speak, several of these drafts are in last call and are about to become IETF RFCs. Driving customer adoption paired with innovation and driving the standards bodies, the VXLAN EVPN ecosystem has expanded from just three to more than 10 in a span of just two years.

Use Cases and Benefits  

With a healthy install base in place, we now have insights into the most important and popular use cases for our VXLAN BGP EVPN solution.

Layer-2/Layer-3 VPN for DC Segmentation

  • Customers can choose to segment their networks at Layer-2 (L2), Layer-3 (L3) or both. Since EVPN carries both L2 and L3 reachability information, it provides support for integrated bridging and routing in overlay networks.

Scaling out the Access Layer

  • This allows flexible workload placement with minimal disruption employing Cisco’s VXLAN Distributed Anycast gateway at the access.
  • Active-Active L2 multi-homing at the access with Virtual Port-Channels is critical for high availability. Cisco has been working diligently on improving re-convergence times during link failure, switch failure/reload and other similar scenarios to sub-second level.
  • Another benefit is optimal forwarding of traffic (east-west, north-south), with no hair-pinning. The solution also minimizes flooding within the network through protocol-based host MAC/IP(v4/v6) route distribution and early Address Resolution Protocol (ARP) termination at the local access switches.
  • This also allows utilization of the full bisectional bandwidth of the network by running VXLAN at the access layer and eliminating the need to run the Spanning Tree Protocol (STP).

VXLAN beyond a single Data Center

  • VXLAN EVPN enabled the industry’s to come up with new data center deployment approaches and optimized ingress routing. The support for L2 extensions crossing not only physical rack boundaries but stretching across data center are only some of the use-cases that evolved as the EVPN control-plane evolves. New innovation around true DCI with flexible scaling, geographically dispersed locations and disaster recovery are just around the corner. Cisco has been spearheading these efforts at IETF with VXLAN EVPN for DCI and is authoring the key drafts. Next to that, the Cloudscale ASICs will enable us to provide true DCI with VXLAN EVPN.


Operational Simplicity

In order to automate the provisioning of their networks, Cisco’s customers have choices with multiple controller options including third party ones. Some customers are also leveraging VXLAN EVPN extensions to different IT automation tools (i.e. Ansible, Puppet, Chef) , YANG models and REST APIs  for their overlay provisioning.  For troubleshooting their overlay network, customers are leveraging VXLAN OAM (Operations, Administration and Management) for network overlay visibility and co-relating the overlay topology with the underlay topology. For application traffic,  tools such as path-trace will trace the specific path for a given flow and provide detailed state information on intermediate switches including the ingress, egress interfaces, the switch load, the statistics etc. This is especially helpful when troubleshooting a fat-tree topology with combinatorial possibility of ECMP paths to examine.

Continued Innovation with Segment Routing

 Customers will benefit from additional innovations that Cisco will deliver on the EVPN based fabric solutions. At MPLS World Congress 2017 in Paris, Cisco is announcing the EVPN based control-plane solution for Layer-3 multi-tenancy with Segment Routing.  This will add another key innovation to select Nexus 9000 Series and select Nexus 3100 Series, available with the upcoming 7.0(3)I6(1) release. By integrating EVPN control plane on top of the Segment Routing MPLS data-plane, Cisco provides customers the ability to deploy high-performing, scalable, multi-tenant datacenters with the ability of path programmability.

Additionally, Cisco is providing consistency of programmable access through common API, YANG models and orchestration tools. With end-to-end path programmability, traffic engineering based on application needs, and multi-tenancy with EVPN, customers get the best of both worlds – a seamless transport with Segment Routing and an efficient control plane with EVPN.

The success Cisco has achieved with the EVPN solution is another example of how Cisco has been innovating in all aspects of IT, enabling our customers to move faster, be competitive, and cross the chasm as full-fledged digital businesses.

Stay tuned for new upcoming announcements regarding BGP EVPN based solutions.

Babi Seal, Senior Manager, Product Management, INSBU


Tony Antony