ChillyJim , I am tired of guys who blame ISA - A proxy . I respect your knowledge in CP but Proxy 2. was a proxy Server in 1996 . ISA is different product.
From 2000 , but a major upgrade in 2004 ,ISA is a product that has the major feature set u find in FW1. Read the books. Stop calling ISA proxy. Yes it can function as a proxy if u wanna use user auth/and rely on ISA for DNS. U can disable this proxy and use the exact same way as CP. Using or not using the proxy , either way ISA users its 7 Layer inspection ( yes the same as CP ) to examine the traffic. ISA is now in hardware. As the fellow guy pointed out ISA has many advantages over CP.
The main disadvantages of ISA 2004 have been :
1. Windows is percived as non-secure operating system. A bad linux thought that was implanted around 1995 - 1999 .For reason. Today it is 2006. This is an era in It.
If u say Windows is not secure today i hear - i dont know how to do it. . An operatting system can be hardned.. Also Windows. It is not hardened by default because it is the most widely Operating system and this is what the market needs. I agree Windows by default cannot be used as an edge device. Needs to be hardened. Common Cretiria 4. Linux recently had only 2. However , it takes knowledge to secure windows. Yes u need to read the books. The very same way u learn how to secure linux or whatever. This is now history. HP sells ISA applince that uses hardned version of Windows. Even a linux guy can secure it now.
ISA will be a major firewall very soon. You will see. With so much money no one can stop u.
Here is a hint that they dont sleep.
http://biz.yahoo.com/prnews/061213/sfw052.html?.v=86