I’d like to thank Soumitra Mukherji for his work on this post!

As of this posting, January 2018, Multipod for ACI has taken off and seen a good amount of field exposure amongst Cisco ACI customers.  There have been a number of customers who were going to deploy either dual ACI Fabrics or  Stretched ACI Fabrics between sites, but it was quite easy to review their requirements and convince them that Multipod was the right choice for their deployment.

However, even with the popularity of Multipod, I think most of you who have deployed Multipod will agree that the learning curve for the Multipod configuration was a bit steep. Given that, I feel lot of people are a bit apprehensive about the MultiSite configuration and intend to set a significant amount of time aside to get up to speed.  I was certainly in the same boat,  but it was a pleasant surprise for me to find out how easy it was to set up Multisite and create Tenants with it.

This post will not deal with the comparison for Multipod vs Multisite. It will also not take a deep dive under the hood technology for Multisite.  There is a lot of good material on that. For starters check out: Cisco Live: BRKACI-2125 session. Another good document for Multisite (including best practices, and general deployment information) can be found on CCO – Cisco ACI MultiSite Whitepaper.

This document will not even deal with how to set up Multisite Controller.  If you are looking for how-to-guide for setting up Multisite from scratch, check out this excellent video by Robert Burns – Deploying ACI Multisite from scratch. 

What is MultiSite?

What are the use-cases for MultiSite?

The Main Purpose for writing this article is to clear up the concept of how to configure Tenants with the Multisite Controller (MSC).  Some of the concepts (Sites/Schema/Templates) were really tripping me up, and I had to draw it out to understand what all of that is about. Once you understand the relationship between Sites, Schemas and Templates, MSC is really very simple.  If you already know ACI, the learning curve won’t be steep at all (a few hours and playing around in the lab).

3 Steps to deploy a new Tenant to two ACI sites

* Note:  In above,

Since TemplateUno is associated SMDemo1-Tenant and that template is deployed to SITE1 and SITE2.

and:

TemplateDos is also associated with SMDemo1-Tenant,  I cannot deploy TemplateDos to Site1 and Site2 also

Now. I built another Tenant (empty shell)  and associated with both Sites.  Then I went into the same Schema, added another Template “TemplateTres” and associated TemplateTres with Tenant SMDemo-2-Tenant.  Then I deployed the new Template to both sites.

Notice: in Diagram Below Site1 and Site2 has both TemplateUno and TemplateTres deployed, essentially (2) Tenants in both Site1 & Site2

Verification on the APICs

Site1 APIC:

Site2 APIC:

Conclusion:

MSC Setup and Tenant Configuration by MSC is much simpler than I expected it to be.

Below is a flowchart of the steps.