SharePoint Outbound Hybrid Federated Search - Configuration

Question

I'm setting up SharePoint outbound hybrid federated search in our environment. That is we want our SharePoint Online data to be displayed in SharePoint on prem search results.

The below Microsoft article explains on how to do it:

https://docs.microsoft.com/en-us/sharepoint/hybrid/display-hybrid-federated-search-results-in-sharepoint-server

On following the article, i see that it describes about server-to-server authentication from SharePoint Server to SharePoint Online but doesn't specify it to be mandatory or a pre-requisites.

Is Configuring server-to-server authentication from SharePoint Server to SharePoint Online a mandatory pre-requisites for Hybrid Federated search to work?

https://docs.microsoft.com/en-us/sharepoint/hybrid/configure-server-to-server-authentication

Answer 1

S2S is required for all hybrid search scenarios in order to validate that the call came from a trusted identity.