So Yeah Firewalls... I Have No Clue, Need Help!?!

Hi there, I am a high school student who is currently very interested in networking and am thinking about pursuing a future career in it. 

I was watching a video on a home network which had a separate box device thingy which was a firewall. I always thought that a firewall was something built into your computer or router?

So these are my questions:

What/why have a separate firewall device, what are the advantages of it? Also what does it do exactly? I know its about computer protection and security and that's about it, so could someone explain it simply please!

Also does a firewall use software that I could put on an old netbook that have lying around? Just to use this instead of a box firewall thing? I'm currently just not worried about practicality and stuff I just want to get my hands dirty!

I don't mean to come across as stupid, I know much about actually pc hardware and have only just come into the magical world of networking! So thank-you so much to anyone willing to leave a quick comment to help me out, its much appreciated, I look up to all the Tek Syndicate crew and hope to one day be like them.

So, if you're really interested in "networking" and you want to "get your hands dirty," then get away from the YouTube videos/blogs/forums and get into the books.  Videos and opinions will only take you so far.  So, get some books and start reading so you have a theoretical understanding of the aspects of networking that interest you.

Agreed ! Get Tanenbaum's Computer Networks 5th edition and learn.
Back to the point though, a hardware firewall is a specially purposed box generally managing WAN access inbound and outbound the LAN, filtering packets depending on the source/destination addresses, type of traffic (NNTP, SMTP, BitTorrent, etc.). The main difference with a local (on your own machine) firewall is the filtering at network level, not local.

All any firewall is going to do is deal with ports by blocking most of them while allowing others to be open (like the very important port 80 or 8080 that you web browser is using). So you may want to start with knowing what a port is - and no, it's not one of those connections on the back/front/side of your computer either. The "ports" I'm referring to are a software thing. Here's a Wiki to help you get a taste of it:

For more, and perhaps some very enlightening "ah-ha" moments, may I suggest watching a Youtube guy calling himself "Eli the Computer Guy"? He did a pretty good "course" on this that is well worth your time to watch (which is also a bit unlikely since it is on Youtube after all too). Here's his web site:

Here's probably the one video you may want to watch which may explain it all right there:

Hope it helps...


Cool thanks for the suggestions guy - I have seen Eli before and his videos are very good, he just didnt have one strictly on firewalls.

much appreciated everyone