ACI Multi-Site spines back-to-back with a Cloud Site?

[m1xed0s]

Say I have two on-prem DCs setup with ACI Multi-Site using spines back-to-back connectivity (NO ISN) in production already. Now I want to connect Cloud site, either AWS or Azure, to this existing Multi-Site architecture, will the setup work and/or supported?

I know the spine back-to-back would only work with two on-prem sites but will it work with two existing on-prem DC running multisite back-to-back plus one new cloud site? I think the answer is negative but can not find the firm answer in any doc...so hope someone here could help share the light.

[Robert Burns · Accepted solution]

If you need to connect more than 2 sites (onPrem or Cloud) then you will need a proper ISN.  This is one of the reasons we really suggest deploying Multisite with an ISN to allow for further expansion.  B2B really limits any growth/expansion options.

Robert