IPsec question

[gonzangus]

Can IPsec in windows server 2003 be used for filtering the traffic from one internal net to the Internet???

[Igor Karasik]

Gonzangus,
I think IPSec can be used in addition to a firewall, but not as firewall replacement.
IPSec filtering lacks logging and
alerting, NAT feature, statefull inspection, any protection against IP spoofing and other things which any basic firewall have.
If you connect your internal network to Internet you will need some type of content security solution (TrendMicro,Esafe,etc) as well (in addition to firewall).
See this link as well
http://securityadmin.info/faq6.asp#firewall

I think also that I misunderstand you previous question (with Subject: "Security question") - windows 2003 built-in firewall can only protect windows 2003 server itself but not entire network - you need ISA or other firewalls for it.

[Ivan Ferreira]

IPsec is used to secure the communication between the client and the server. Is not used for packet filtering. You could in fact, assign a policy that rejects insecure communications on the client, but the performance costs of ipsec is too high to enable it if you don't really need it.

You should use an ISA server or another firewall solution for this purpose.