Transcript FIREWALLS
FIREWALLS Created and Presented by: Dawn Blitch & Fredda Hutchinson What is a Firewall? • A Firewall is simply a program or hardware device that filters the information coming through the internet connection into your private network or computer system. History of Firewall • First Generation-(1985) First security firewalls appeared. Network layer IP routers with filtering rules that had to be manually changed by the administrator. (Must have intranet access or valid IP address) • Second Generation-(1989-1990) Circuit level firewall gateways that prevented direct connections between networks through address authorization. History of Firewalls • Third Generation-(1991) First commercial firewall (DEC SEAL), Used filters and application gateways or proxies. • Fourth Generation-(1994) Check Point Technologies, Firewall-1, developed “first user friendly” firewall. Used dynamic packet filters that dynamically changed filtering rules. History of Firewall • Fifth Generation-(today) Kernel Proxy architecture, which evaluates network packets at multiple layers of a protocol stack in the proxy server. Types of Firewalls • Network Layer-A hardware firewall that controls what packets or information that are passed in or out of your network Types of Firewalls • Application Layer-Software that does not allow direct connections between networks, which performs logging and auditing of traffic. How Firewalls Work Cautions • Remote Login • SMTP session hijacking • Operating system bugs • Denial of Service • E-mail bombs • • • • • • Macros Viruses Spam Redirect bombs Source routing Application backdoors Firewalls may only limit these items to an extent. The level of security you establish will determine how many of these threats can be stopped by your firewall. The highest level of security would simply block everything, this would defeat the purpose of having an internet connection. Basic rule of thumb for all administrators is to first block everything and then implement rules which allow only certain information or packets to pass. Why would I want a Firewall? • To keep hackers out of your network while still letting you get your job done. • Plays an important role as a security blanket for management • Mainly just to help • Gives you a place to store secure information that people in your corporation need access to. Do They Work? • To simply answer this question, they work to an extent, but of course, if a true hacker wants your information they will stop at nothing to get it. And as always, there are accidents that do occur when testing new software, such as probes. So just be cautious! Websites for Firewall Products • • • • http://www.mcafee.com http://www.checkpoint.com http://www.smartsoftwareshopper.com http://www.netscreen.com Sites Used • http://www.interhack.net/pubs/fwfaq/ • http://computer.howstuffworks.com/firewall .htm • http://dmsweb.badm.sc.edu/mgsu890/fire walls/fire2.htm