A firewall is a security device that is designed to protect a local area network from unauthorized intrusions. The firewall analyzes traffic and applies rules between the local network and external network. There rules are based on IP addresses and ports. In order for a computer to connect to the internet, it must have a unique IP address that is different from other network devices. A computer provides services on the Internet by using port numbers. For example, port 80 corresponds to “http” service. Port numbers range from 0 to 65536, but only ports 0 to 1024 are already defined as well-known ports.

A firewall prevents harmful and unsolicited incoming traffic from accessing computers or other networked devices. The intention is to keep hackers from gaining unauthorized access to a machine.

Hackers usually exploit vulnerabilities of existing well-known ports. The firewall protects machines inside its perimeter by blocking these ports from the outside network.

• Secure Zone
  All incoming traffic to your computer will be blocked. However, computers behind the firewall can initiate access to outside servers.
• Semi-Secure Zone
  Some incoming traffic to your computer will be blocked. Currently, the following well-known port numbers will be open: Port 22 (SSH), Port 25 (smtp), Port 80 (http), Port 143 (imap), Port103 (pop), Port 443 (https), Port 3389 (terminal service).
• Unprotected Zone
  This zone is your current zone with no firewall protection.

* Please see your department tech or security@ssc.ucla.edu if you require customized security levels.

Network access will not be affected by the firewall. The firewall restricts unauthorized access from the outside, it does not restrict access to the Internet.

YES! The firewall only examines IP address and ports. Many viruses and worms are sent through e-mail as attachments. Therefore, it is important to use virus protection software and keep it updated with the latest virus definitions. The firewall may stop propagation of some viruses and worms, but it does not protect users from opening harmful email attachments.

YES! It is highly recommended that computers are updated and patched as to ensure maximum protection against viruses and worms.

NO, the firewall does not affect these protocols. The firewall will only filter IP traffic.

YES! Having a personal firewall allows for more customization and allows the user to further lock-down their computing environment.

Please contact your department tech or security@ssc.ucla.edu for more information.