Application level inspection - firewall?

[Chuck Swiger]

Paul Hillen wrote:
> Quick question, is there an Application Level firewall available to FreeBSD.

For some definitions of that buzzword, sure.

> I understand IPFilter is a stateful packet filter, but has it or any other
> packages moved to the next level - Application Level Inspection?

Squid plus a firewall which blocks or redirects port 80 will serve for HTTP; 
Postfix or Qmail or whatever plus firewall rules which do the same for port 25 
serve as application-level filtering for SMTP (enough to protect that Exchange 
server some people want to run), etc.

-- 
-Chuck