The Challenge

Operating a network can be a daunting task. Especially when you find yourself manually repeating ordinary work on a regular basis. As a network engineer you are likely to enjoy challenges with protocols and designs rather than unboxing, mounting, and installing hardware. The time spent on this everyday work should be kept at a minimum. In a streamlined network design, the configuration of new equipment should be based on a template with few variables, such as hostname and IP addressing. Many companies already practice using templates, but for the most part the engineer must still manually adjust these variables, or at best some advanced excel spreadsheet or flat text file is used with a manual search and replace to build new configurations. Next, the device is powered up, connected to with a console cable and the newly build configuration is pasted into the device before installing it in its final location. Oh, and now both software upgrade and licensing tasks must be performed to be compliant. The workflow is manual, time consuming, and worst of all error prone due to the inevitable human factor.

Introduction

ISIS is the routing protocol preferred for SD-Access (SDA). Roughly said, SDA is somewhat similar to routed access. We can think of fabric edge nodes as access switches when comparing them to our traditional flat networks. Many companies buy multiple switches and deploy them in stacks using Cisco StackWise technology. This has the usual benefits of stacking, namely collapsing all of the switches in the stack into just one management and control plane. We might see something similar to the below topology with SDA.

Unfortunately not all Cisco platforms support SDA. Cisco has chosen these platforms to be extended by SDA to be able to offer both a desktop platform and IoT platforms:

• 3560CX
• IE 3300
• IE 3400
• IE 3400H
• IE 4000 series
• IE 5000 series
• Catalyst Digital Building

NOTE! If you plan on using policy, meaning micro segmentation using SGTs, only IE 3400 and IE 3400H are supported as policy extended nodes!

Extended nodes must be connected to a single (or stacked) edge switch (excluding Catalyst 9200).