A personal firewall will have a variety of levels of protection that depends on whether your computer is connected to the Internet or to a network. A computer on a home network will often have shared files with other computers on the network and will also access the same resources, such as printers. If this is the case there will be more access than if the computers are connecting to the Internet.
Connecting to the Internet is risky and needs to be controlled. Firewalls should be set to restrict certain data that is outgoing and incoming as well as close any ports that aren’t being used. A port is a standardized number that routes Internet traffic with the use of network software.
You don’t need to be a computer expert. Most firewall settings are configured according to default. If you need to modify these settings you’ll usually get an alert when you’re making the change.
There are two basic components to a personal firewall. The first component will look at the data when it comes into your computer to decide whether or not the data should be allowed to pass through. The second component will set up certain policies for some applications. These policies can be relaxed since they simply let certain programs have access to the Internet.
The first component is known as the “packet filter”. This filter will take a look at each packet of data and will let it pass through or let it drop. These packets are composed of data that is routed on the network. There are rules for these packets, which are called polices, that let data pass or decide which data fails to meet the policy standards. Failure to meet these policies will give an alert or else just drop the packet depending on how the firewall has been configured.
The second component is known as the “application filter”. This filter will decide whether certain programs are allowed to receive and send data through one port or another. A browser will need to have access to the Internet so a policy is put into place that allows the receiving and sending of data using Port 80, which is a standard number.
Just because the web browser is using Port 80, and other ports are blocked by the personal firewall, your computer still won’t be secure.
An application filter is set up for certain programs and not the particular components of these programs. Every program will have more than one module, each of which can be infected. In a Windows environment these are known as DDLs (dynamic link libraries).
In most cases your antivirus software will be able to determine if a module is infected but any new viruses, that are not yet part of the antivirus database, may slip by undetected. Your computer system will be vulnerable if your personal firewall allows this to happen.
A firewall won’t give you complete protection against viruses and hackers. A firewall is only effective for keeping some hackers out of your system and you should supplement your system with antivirus software. You should also practice safe file sharing procedures.
There is one main rule to follow with firewalls: If you don’t know what is trying to accessing your computer consider it a risk.
By: Paul Wilcox
Posts Tagged ‘Firewalls’
Using Firewalls to Protect Your Computer From Attack
March 22nd, 2010Securing Your Home Network
February 20th, 2010
You have probably read about how people are able to gain access to an individual’s computer and essentially steal all their personal data. There are many ways that this can be done without the owner even knowing that someone is trawling around within their computer right under their nose. There a few simple steps that you can do to safeguard your personal information from internet predators.
Your home network is your first step to securing your personal data from the outside. You should have a secure perimeter network that stops any potential intruders from accessing your data. It is by far better to stop intruders at the perimeter rather than at your computer. Make sure that you have a hardware firewall enabled at the point where your home equipment connects to your internet connection. Hardware firewalls are more difficult to hack and do a good job of keeping unwanted eyes from seeing your personal computer.
A hardware firewall for homes normally comes in the form of a router. Some people have a modem connected to their internet connection but these do not come with a hardware firewall and are not secure. Make sure that you are using a router with a hardware firewall between your computer and the internet connection. If you are not sure which one has been supplied by your service provider, have a look at the original documentation or phone your service provider and ask them.
Most routers provided by internet service providers are wireless. This means that if you have a laptop, you can connect to the internet using a wireless network card from your laptop to the router, and finally out onto the internet. Even if you don’t have a laptop and use a desktop computer, the router from your service provider will still have the wireless functionality enabled. This wireless connection broadcasts a name called an SSID. This can be picked up by any wireless device normally within a 50m radius of your home. You need to make sure that the wireless broadcast is switched off if you do not use it. If you have a laptop and use it to connect to the internet wirelessly, make sure that it uses an encryption key to secure all communications. The older type of encryption is WEP and is now less secure; you should be using WPA which is more secure. Read the documentation that came with the router on how to configure encryption on your router.
By: Mike JJ Johnson
