What is a firewall?

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What is a firewall?

A firewall helps safeguard your computer or home network against unwanted, outside access. Properly configured firewalls can help protect your computer from hackers, worms, viruses, Trojan horses and other security attacks. These malicious programs may also use your computer to attack other computers. A firewall acts as a wall to block these programs and hackers from accessing your computer or home network. This is important for both dial-up and high-speed users since all computers connected to the internet are at risk of becoming a hacker’s target, especially if they do not have a firewall.

Hackers or malicious programs may try to access your computer or home network for a number of reasons, such as gathering personal or confidential information about you, accessing your Internet Service Provider (ISP) or copying private documents stored on your computer. Some hackers are simply looking for the challenge. It is important to keep any firewall software up to date since the methods used for bypassing firewalls change constantly.

Like any security system, no firewall is fail-safe, but when used in conjunction with other security measures such as antivirus software and good safety habits, a firewall provides enhanced protection every internet user should have. It’s important to remember that antivirus software is not a substitute for a firewall. Check out AOL Internet Security Central for more information about online safety and spotting scams/schemes.

Good online safety habits are:

  • Downloading files only from trusted, known sources
  • Never giving out personal information to sites you don’t trust
  • Password help


How do firewalls work?

Most firewalls offer different levels of security that control the flow of traffic from the internet to your computer. For example, a firewall can allow all traffic, allow only the traffic that you designate as trusted or block all traffic to your office or home network. The firewall does this by monitoring the programs on your computer that access the internet. Your preferences designate the security level of your firewall.

What are the different types of firewalls?

Firewalls come in a variety of forms and provide varying levels of customization, features and updates. They may vary from hardware devices such as routers to software programs that you load onto your PC, or may even be bundled with your computer's operating system. These firewalls range in price and may be free downloads, one-time purchases or subscription services. Some common firewall options are:

  • Software firewalls: Many vendors, such as McAfee, Symantec and Zone Labs, offer free or premium firewall software that you can download from their websites or purchase at retail locations. Software firewalls require security updates from the vendor to maintain their effectiveness. Setting your firewall preferences to auto-update will increase the firewall's security capabilities.
  • Router- or gateway-based firewalls: Many broadband home networking routers (or gateways) include a built-in firewall as a basic feature. A router-based firewall can help protect all of the computers on your network by preventing unwanted traffic from traveling through the router and being sent to the computers.
  • Operating system firewall support: Examples of this type of firewall can be found in Microsoft Windows XP or Macintosh OS X. These firewalls are embedded in the operating system and may need to be turned on.

How do I choose a firewall?

If you are setting up a home network, you should purchase a router or gateway that has a firewall as a standard feature. Some people with a router-based firewall also prefer the added security of a software firewall for each of their connected computers. If you don’t have a home network or a router with built-in firewall protection, AOL offers the McAfee Internet Security Suite.

How do I use firewalls with game consoles?

PS2 users may experience problems connecting their game console behind a firewall. The easiest way to avoid a firewall conflict is to connect your game console's network adapter directly via Ethernet to your cable or DSL modem.

Note:You may still experience problems in connecting to specific game servers or hosting online games.

Why do programs request internet access?

A program (for example, explorer.exe, rundll.exe, or svchost.exe) might be called by another program to communicate with the internet. Some of the other reasons why a program might request internet access is to:

  • Check for automatic updates
  • Retrieve information such as email, news or music
  • Communicate with a licensing server to verify your right to use the program
  • Communicate with a server to submit your registration information

Why do programs request server access?

A program might request server access if it expects to receive anonymous connections from the internet. Examples of this include some online games, messenger applications and file-sharing applications. You should only allow an application server access if you recognize and trust the application and if you want it to be able to receive anonymous connections.

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Last updated: 08-04-2014
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