The EnableWebFarmSupport setting is an obsolete
AppSettings that could be added to the web.config file in DotNetNuke 4.x versions. By default EnableWebFarmSupport was set to false. If your DotNetNuke 4.x site is configured to use the
FileBasedCachingProvider and EnableWebFarmSupport is set to true, then the framework will ensure that all servers in the farm keep their caches in sync.
The EnableWebFarmSupport setting is not applicable if any caching provider other than FileBasedCachingProvider is used.
This setting is replaced by the
IsWebFarm in DotNetNuke 5.x.