Should I use a firewall?


My computer uses a router DSL-500g to connect with Internet. I have Comodo Firewall installed also.
But why shoud I use a firewall if the router controls the trafic?

Thank you!

These type of questions will come up more often.
So which hero of Comodo will be brave enough to compile an FAQ about why they should use the firewall.


  1. Not sure that I am up to a faq. A static firewall on your router is a good idea but you need a firewall on each computer that connects to the router or lan connection. These are more easily updatabel than your router firewall and probably are updated more often. Most of the guru’s will tell you that you need a multiple line of defence (check out the langalist (my favorite)) You should also have and run frequently anti mallware programs as well as a good antivirus program.

here is an article thats identifies one of the reasons why we should use firewall.

Comodo research shows that over 50% of desktops have been converted to zombies. They are possessed by unwanted programs that use the host computer to send spam, or steal confidential information.

If you think you are safe, because you are using anti-virus and anti-spyware software, think again. You may already have spyware happily calling your computer home.

A/V and A/S programs are like cops that only look for murderers by using photos. No photo, no way of identifying the murderer.

But how do you handle a new virus or a new spyware that your A/V and A/S software does not know anything about?

That’s what a modern Personal Firewall is useful for, providing you visibility about who is making a call home from your machine. Yes, they also protect you from people trying to hack into your machine, but the real value in this spyware-ridden computer world, is providing you the visibility about your connections. Who is connecting to what, both to and from your machine.

How will you know if the personal firewall is good enough? One way is to run a leak test on your firewall. If your firewall leaks, then it won’t protect against malware that is calling home.


Why should I use a software firewall if I have a hardware firewall installed?

Well I thinked like this when I bought my router with integrated firewall, some months ago, and after some considerations I decided to keep my software firewall also. Here are some of the reasons that is necessary to use a software firewall:

1.Hardware firewall protects from external attacks and from some types of protocols, but it does not know what applications on our computer send the data to the out world.

2.The above could make people think that if I use only safe applications then I am protected; right?
Wrong. This is the biggest mistake one can do. Since all of us use internet for comunicating and navigating to sites we cannot be sure of all the data that we receive from the outside world. If we receive a virus then in the worst cases we will lose personal documents, will have to reinstall our operating system or in rare chases say goodbye to our hard disk.

3.But what happens if we receive other type of malware programs? If we receive a troian or a worm? Those can use our computer and our connection to send themselves to other computers and infect them to, or in the worst chase steal our confidential information such as name, bank accounts, visa card numbers,etc. and send it to the person that made them. Will the hardware firewall protect us?

4.The answer is no. The hardware firewall cannot know which application sends the data to the outworld. Only knows that is being send by our computer, which the hardware firewall consider safe. And here comes the necessity of using a software firewall.

  1. This last one will check which application is trying to send the data in the outworld and will warn us. Then if we consider it a safe application we can allow it to send this data; or we can block it if we consider it unsafe. That is the one use that software firewalls offer and which hardware firewalls don’t; it tells us of which applications connect to the internet.

  2. And this is the reason that is necessary to have. Antivirus programs will warn us and block Known threats. Software firewall will inform us also about unknown threats (that connect to the net), and let us block them before they can really harm us. :wink:

ps. I tried to explain the need of a software firewall in the simplier way I could, I hope that it will help novice users understand some of the threats that are out there.

by pandlouk

Thanks for the faq it covers all the points I missed and says it better.

Thanks erasmus ;D

Thnx for the info pandloux, very interesting, :SMLR