I have two different SharePoint farms, one with tons of sites and lots content and one that is primarily a portal site. These farms are in the same Active Directory domain but in different data centers, on different servers, and with different service accounts.
The farm with all of the content is already searched and indexed by that farm's search service just fine. I have no interest in re-crawling and re-indexing a farm that is already crawled and indexed.
However, when someone searches on my portal farm, I want to return results from both the portal and the large content site. As I was reading the information on Search Federation, that seemed promising but I am not seeing SharePoint to SharePoint configuration guidance.
What am I missing?