In 2010 and 2011, Software Defined Networking (SDN) was the hot new way of looking at architecture, and everyone had high hopes that it would reduce the stress of highly manual and complex operations. That was then, but now we’re in 2018 and it appears that SDN hasn’t quite fulfilled what it advertised, as many networks remain expensive, complex and proprietary. Some may claim that SDN is dead, but perhaps that’s not the case; maybe SDN has changed from its previous understanding and taken on a new definition. With solutions like EVPN and freedom from proprietary controllers bringing it back to life, SDN has risen like a phoenix from the ashes to finish the mission it started. How did we get here and what’s changed? You can check out our white paper for a more in-depth, technical look at SDN’s journey, or you can keep reading here for a CliffsNotes version of the information.

A link to the past: what SDN promised us

SDN promised to enable the network to behave like the server world, where resources could be virtualized and new environments could be deployed or decommissioned almost instantaneously. SDN sought to break-up the vertical stack by moving the control plane of the network outside the operating system, and to utilize open protocols to access switches and routers. The promised benefits included on-demand provisioning, automation, agility, scale and simplified management.

So, what happened?

In short, controllers happened. Most networking vendors sought to maintain their dominance and reign of networking by creating proprietary SDN controller offerings like Cisco ACI and Juniper Contrail. Big Switch’s Big Network Controller followed this path as well. These offerings put the control plane in a separate control box, which only controlled their own infrastructure. So there went the promise of agility and control. Companies like VMware and projects like OpenFlow attempted to create open controller solutions, but they unfortunately had huge scalability and interoperability issues. At the end of the day, SDN was vendor-dependent, expensive and unable to scale — virtually the opposite of all the goals it was meant to accomplish.

Never fear, EVPN is here!

As you can probably tell, the majority of SDN’s problems stemmed from the use of controllers. The simple solution is of course to get rid of controllers entirely, but then how can you manage all your VXLANs? That’s where Ethernet Virtual Private Network (EVPN) can step in to assist. EVPN is a standards-based software solution for a controller-less VXLAN solution. It provides a scalable, interoperable, end-to-end control-plane for VXLAN tunnels using the tried and true communications protocol BGP. Without proprietary controllers holding it back, SDN with EVPN demonstrates that this architecture isn’t dead — it’s simply evolving.

Cumulus Networks positions EVPN as a controller-less SDN solution that makes networking more simple, scalable and interoperable. As a next-generation control-plane solution for VXLAN tunnels that uses the BGP routing protocol, it provides highly scalable and redundant traffic engineering, multi-tenant separation and fast convergence for host and VM mobility — all while interoperating between vendors. It also gives data center operators the standards-based, vendor-neutral solution they need to preserve critical data center connections as they take their businesses to the next level. At the same time, it simplifies infrastructure, reduces effort and lowers costs. Because the intelligence resides in the control plane, when VXLAN nodes are added, the control plane is immediately aware and VXLAN nodes automatically speak to all of the connected servers. Cumulus EVPN eliminates the need to broadcast ARP and removes dependencies, simplifying traffic flow and delivering flexibility to redeploy infrastructure as needed. With EVPN, SDN becomes the open, agile solution is was always meant to be.

Help! I’ve already invested in an open SDN-based controller! What do I do?

If you have invested in one of these open SDN controller offerings — like OpenContrail or VMware NSX – Cumulus Networks becomes the perfect joint solution. Since you still need a physical underlay to work with your open SDN controller, Cumulus can become the physical underlay with white box switches using an open operating system in Cumulus Linux. Whether it’s integration with open SDN controllers, private clouds or big data, Cumulus can help drive the promise of using the network simply as code.

Ready to start testing out Cumulus Linux? Cumulus VX is an absolutely free virtual appliance that enables you to test out our open technology — try it today!