I have an ADSL modem connected to a broadband (like linksys, USR8000 ...) routeur (NAT)that is used to share an internet connection. I would like to connect an ISA server to the router and then from the ISA server go to a hub to which several PC could be connected . The IP adress from the router is 192.168.123.254 and is getting from the ISP all IP infos (ip adress, subnet mask (255.255.255.255) the gateway,and the DNS. Question is: How should I configure Ext. and Int IP settings ( IP,subnet,gateway, DNS.....) from the ISA server to have the integrated mode (firewall and cache) , and what should be the settings of ISA to be able to have MSN messenger not blocked? Any help will be appreciated.....