Worth a read!
Many data centers include firewalls between the end-users and the servers and other integrated systems that support an implementation of Microsoft Dynamics CRM 4.0. This document provides guidance on the connectivity requirements between Microsoft Dynamics CRM 4.0 and other systems to assist readers with proper firewall configuration in customer environments.
This white paper, The Microsoft Dynamics CRM Security Model, serves as the core architectural component of a larger “nuts and bolts” article on Security and Authentication in Microsoft Dynamics CRM 4.0. The paper details the security model leveraged by Microsoft Dynamics CRM 4.0, including information on the authentication mechanisms that, depending on the deployment model, support Microsoft Dynamics CRM. In addition, the document provides details about how access to Microsoft Dynamics CRM 4.0 system resources by users and external systems can be controlled and restricted.