SD Access into traditional networking

[AlexWong123]

Hi, I am new to Software-Defined Network. Currently upgraded a building of old switches into Catalyst 9K series with still a traditional networking.  If implementing SD Access into the traditional networking by using DNA Center, do I have to manually config underlay and overlay network (like IS-IS, VXLAN... sorry I am not very sure, still researching on this) in the switches, or DNA Center has the automation to push the underlay and overlay configuration into hundreds of switches without overwriting their current configurations?  I am very thankful if someone can help answering this.

[Preston Chilcote]

It will help your thinking if you plan for a device to be either part of the fabric or not, but not both.  So you won't have to worry about overlapping configurations.  The fabric underlay configs can be automated by a feature called Lan Automation.  Here's a brief intro video that hopefully introduces you to the concept and terminology for you to research further on your own:

https://www.youtube.com/watch?v=OZav15M6E_0

Cisco Live videos are a great place to learn in more detail from some really great presenters.

Note: the GUI might have changed a little bit since the video was recorded, but the concepts have not.

[rasmus.elmholt]

As Preston says the underlay can be done in 2 ways. Manually or with LAN Automation.

If you do it manually you have to make sure routing is available between all the Fabric devices(FE, BN, CP) and their Loopback interfaces(used by LISP and VXLAN).

With LAN automation you can get the DNAC to provision the underlay for you according to Cisco best practise.

On the Overlay part the DNAC will provision all that stuff for you as long as you have made you Design/Intent clear to the DNAC.

There are a lot of brownfield migration scenarios available in some of the old Cisco Live slides.