Question
What is a firewall?
Answer
A firewall acts as a protective barrier between your computer and the Internet, monitoring all incoming and/or outgoing traffic and allowing only the network traffic you permit. Firewalls come in the form of software, which nestles itself between your operating system and your network card. They also come in the form of hardware; for many home and small office users, it is a simple router device that sits between your computer's network jack and the wall connection. You can customize the level of protection the firewall gives you, setting it to filter information flow from specific domain names, addresses, or network traffic.
How does a firewall work?
Hackers search the Internet in a way akin to dialing random phone numbers. They send out pings (calls) to random computers and wait for responses. Firewalls prevent your computer from responding to these random calls. If your computer doesn't respond, hackers won't know it's there.
What are the risks of not having a firewall?
If your computer, like most, is automatically set to enable file-sharing or to keep network ports open while you are online, you could be susceptible to a variety of attacks. If you don't have a firewall, which will monitor ports to stop unwanted traffic from slipping through, you have to know how to manually close ports, and disable file sharing, in order to control risky traffic from coming in to your computer.
What do I need to know before installing a firewall?
- Consult your computer's security settings option to determine if you have a built-in personal firewall. If you do, turn it on. Be sure to consult with your department's Technical Support Coordinator before turning on a personal firewall on a departmental computer.
- A firewall is not the single solution to computer problems. As with other computer security measures, malicious programs disguised as friendly ones can circumvent a firewall.
- Like any add-on to your computer, a firewall can interfere with other applications on your system.
- Firewalls might prevent campus vulnerability scanners from alerting you to a problem on your computer.
- Depending upon which department and network you belong to, there may be restrictions on the use of personal hardware firewalls/routers.
- If your computer comes with basic firewall capacity, or if you are thinking of installing a firewall, you should contact your tech support person first. Faculty and staff should consult with their department's Technical Support Coordinator before installing a firewall. Students can contact IT Express, 530-754-4357.
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