cherezoff - stock.adobe.com

Answer

Intent-based networking vs. SDN: How do they differ?

When it comes to the primary differentiators between intent-based networking and SDN, abstraction and administrator commands are at the top of the list.

John Fruehe
By
Published: 17 Jan 2019

Intent-based networking and software-defined networking are similar in many aspects, but they also differ. Both technology approaches rely on a centralized controller to manage distributed devices on the network, as opposed to individually managing each device from its own management console, which is typically a command-line interface. The goal of both approaches is to abstract the management from individual devices and align it closer to how the business needs to operate.

Both software-defined networking (SDN) and intent-based networking (IBN) have the ability to comprehend network configuration and interaction across multiple devices. If, for instance, traffic needs to flow between two servers over a series of switches, either technology approach enables an administrator to define how that traffic should flow and apply those rules across a series of devices -- all with a single command action. The SDN and IBN management controllers understand all of the devices in the chain and the configuration changes that must take place.

Intent-based networking vs. SDN commands

This second-level abstraction is the primary difference when it comes to intent-based networking vs. SDN.

Where the two approaches differ is in how they are addressed at the administrator level. SDN abstracts the management control from the devices, but it continues to have a device-centric view of the network.

Commands in the SDN world are primarily about how devices should operate. Take the following SDN command regarding virtual LAN traffic: Allow traffic between 10.35.291.18 and 10.35.291.22, but only if the traffic is tagged for VLAN 200. In this case, the SDN controller looks at all of the devices between those two servers and sets up rules to allow traffic to flow between the two, as long as it is on the right VLAN. But this interaction is device-centric.

With intent-based networking, the commands are abstracted at a higher level, taking them from being device-centric to being business-centric. Instead of issuing management commands that comprehend IP ranges, device names or types, VLANs and other networking constructs, IBN commands are issued from a business perspective.

For instance, an IBN command may look more like the following: Allow accounting applications to access XYZ server, but do not allow manufacturing applications to access. From there, the management application will determine the devices and routes that match the business intention and will then make the appropriate configuration changes. This second-level abstraction is the primary difference when it comes to intent-based networking vs. SDN.

Next Steps

10 important components of SDN controllers

Dig Deeper on Network infrastructure