two questions about Isa Server

[Marta]

Hello everybody,
I have two questions about this product:
1) I have an Isa server with the Web Cache Mode installed, and integrated in the Active Directory. I would like to know what I have to do to install also the firewall mode: Do I have to unistall the whole product or can I add the firewall part??
2) I would like that clients would automatically know which Url??s are internal (I have a lot of network segments )so that when connecting to an internal Url, they don??t connect to the proxy. Do I need the firewall part to do this? And the firewall client software?
Please, give me as soon as possible your opinion and I would be very thanked to you.
Again thank you very much.


Marta