Once upon a time in a galaxy far, far away, there were networks and network engineers. Then, programmers came and started to take over. Well, maybe not completely, but the networking space has gotten a whole lot more crowded with skill sets since terminologies such as Software Defined Networking (SDN) started popping up in the galaxy that we call networking. 

But what is SDN, and what are the benefits of software defined networking? Below, I’ve dissected these matters and broken them down into easy-to-understand terms. 

What Software Defined Networking Is

Software Defined Networking (SDN) is an approach to network management that enables dynamic, programmatically efficient network configuration in order to improve network performance and monitoring making it more like cloud computing than traditional network management.[1] 

SDN technologies are meant to address the fact that traditional networks are complex and, for the most part, cannot be managed centrally. Traditional networks could stand to be more flexible and easier to troubleshoot, too.

The Benefits of Software Defined Networking

Ok so those are some of the shortcomings of traditional networking, but what are the benefits of Software Defined Networking (SDN)? Since 2004 when the Internet Engineering Task Force (IETF) published RFC 3746 and technologies like OpenFlow and OpenDaylight popped up in 2013, SDN has matured a lot. It has drawn major players to the mix like Cisco with Application Centric Infrastructure (ACI), Digital Network Architecture (DNA), Network Services Orchestrator (NSO), Intelligent WAN (iWAN) and Software Defined WAN (SD-WAN), to name a few. 

For the purpose of this article, I will look at Cisco’s Application Centric Infrastructure (ACI) and some of the benefits of using software-defined networking over traditional networking in the modern Data Center: 

  • From an operations standpoint, ACI will allow network teams to simplify management and operations across the network by providing a common place to manage and enforce policies. 
  • One of the biggest benefits of using software defined networking is that it offers a single point for provisioning.  The networking team would now be able to use CLI, GUI and Programmatic means to deploy configuration to the Data Center fabric.
  • ACI will allow the network team to have visibility into both physical and virtual workloads on the network (with VMM integration, fabric can see VM attributes). You can also integrate Containers for microservices management.
  • It improves the ease and speed of deployment. Once the ACI objects are built they become re-usable. How long does it take to add a new VLAN to all the switches in your environment today?
  • SDN allows for Application Network Profiles. These will enable the networking team to define the policies and interdependencies of an application in the network. This works well for tiered applications, allowing the definitions of L4 – 7 services policies.
  • Automation (DevOps etc.).
  • It strengthens security (ACI is a whitelist model). This means that there is no communication between EPGs unless network policy explicitly allows it. The networking team may want to silo services (DHCP, LDAP, etc.) into EPGs and then define access to these services using Contracts.
  • The networking team will have faster troubleshooting for Day 2 operations – The Dashboard (Health Scores for physical and virtual network elements, application-based health scores, fast troubleshooting via health score drill-down).
  • No more spanning-tree (Non-Blocking) or flooding in the ACI fabric. ACI was designed with EAST/WEST traffic in mind, to allow traffic to flow from physical and virtual servers in the best possible way.
  • ACI allows for ISSU, providing that devices are dual-homed and for the systems/devices that are not. You can do scheduled upgrades automatically for times when these systems and/or devices are least used.
  • It streamlines configuration management.  ACI’s configurations are for the entire fabric, making backing up and rolling back all the devices in the fabric a simple process.  

The main purpose of a data center fabric is to move traffic from physical and virtualized servers, bring it in the best possible way to its destination, and while doing so, apply meaningful services such as:

  • Traffic optimization that improves application performance
  • Telemetry services that go beyond classic port counters
  • Overall health monitoring for what constitutes an application
  • Applying security rules embedded with forwarding

Cisco’s ACI uses software defined networking to streamline operations and improve security for the modern Data Center on its own.

Using SDN Is Always a Smart Move

These compelling benefits of software defined networking are just a handful of the ones that you can experience. By looking at the few reasons that I listed above you can see that Cisco ACI enhances functionality and agility in today’s Data Center.