Microsoft SharePoint 2010 Unleashed

Isolating SharePoint with Separate Physical Farms

The last, most secure, and also most expensive option for SharePoint security through isolation is by deploying each site collection on separate servers or in separate networks. By deploying on separate servers, a great deal of independence is achieved as attacks and snoops from one site are physically removed from the resources of another. This can prove to be expensive, however, because individual servers need to be purchased, configured, and maintained.

The ultimate security boundary for interconnected networks is to simply disconnect them from each other. It goes without saying that the most secure SharePoint farm is the one connected to an isolated network. There are some major disadvantages ...