Levels map to the OSI layers of TCP/IP.. Level 3 is network level or level 7 is the application level. At level 7 the firewall can differentiate the applications such as HTTP or SMTP.. There are many pros and cons (speed, security etc..) Check out: NIST's SP 800-41 Guidelines on Firewalls and Firewall Policy @ http://csrc.nist.gov/publications/nistpubs/800-41/sp800-41.pdf
FYI, yinal. -----Original Message----- From: David Campbell [mailto:[EMAIL PROTECTED]] Sent: Monday, April 01, 2002 3:27 PM To: [EMAIL PROTECTED] Subject: Firewalls What is the difference between the various levels of Firewalls. My current requirement is comparing a (router-based) level 3 firewall to a (PIX) level 7 firewall. Can anyone explain the differences? Does anyone know of a good resource that defines/compares the attributes of firewalls of different levels (perhaps in tabular form)? Thanks, Dave
