Hello There, I am in the process of Integrating ISA server with a PIX firewall and mainly wants the ISA server to provide caching. I have 2 designs in mind. Design 1 PIX with 3 interfaces in a DMZ mode. Interface 1-->Internet Interface 2-->Public servers (Email and web) Interface 3-->Local LAN Design 2 PIX with 2 interfaces Interface 1-->Internet Interface 2-->Local LAN Public servers between perimeter router and PIX public interface. Firstly, which interface gives the maximum security and efficiency? Secondly, where do a place the ISA server, which provides caching for the outgoing requests from the LAN. Thanks for your help guys. Shivi.