I have a SharePoint 2010 deployment where the SharePoint server sits in a DMZ outside of a firewalled domain and individual accounts are set up on the server to then authenticate to the SharePoint site. The backend is a SQL Server 2008 server inside the firewalled domain. I am trying to set up my first External Content Type. I get to the database connection screen. I know what the server is and the database name. I don't know which to select between Connect with User's Identity, Connect with Impersonated Windows Identity, and Connect with Impersonated Custom Identity.
I have read articles and watched videos on having to go into Central Administration and set the permissions once the content type is configured, but I can't seem to get past this step.
Any help or guidance with this would be greatly apprecitated.