Firewall's

So what in the name of God is a firewall thingy anyway?

Easy .....

Let's use our imagination here for a bit, it will make for an easy explanation.

You tell your children not to speak with strangers, and sound advice this is too.

So let's imagine we have one of them office partition type walls, you know the ones you can move around, on one side is your child on the other a "stranger".

The stranger initiates a conversation with the person on the other side by saying "Hello".

If your child does the right thing, he/she will not reply, the stranger on the other side now has no way of knowing if their is anybody on the other side of the wall.

If your child reply's by saying "Hi"then the stranger does know that someone is on the other side of the wall, he can tell ( with a fair degree of accuracy) if it is a male or female, make an educated guess at their age, and using all this attempt to further the conversation.

You can see , that just one word "Hi" as a reply has given the stranger on the other side of the wall a tonne of information!

But as noted if your child makes no reply , the stranger is completely in the dark and has no way of knowing that there is someone on the other side.

So you can see the importance of saying nothing in such circumstances.

By applying this simple scenario to our computer we now get the gist of how a firewall works.

Your computer is sitting there minding it's own business, another "stranger" computer somewhere out there in cyber space says "Hello".

Without a firewall, your computer will probably say "Hi" back. The stranger computer will from this simple reply know that your computer is there.

The stranger computer may well be able to tell which Operating System it's running, it's version, other useful information can also be gleaned.

Armed with this info the stranger computer can now set about it's task, namely to gain access to your computer!

However with a firewall in place your computer will make no response back whatsoever, as far as the stranger computer is concerned your computer does not exist.

The stranger computer will move on and say "Hello" to some other computers till one talks back.

  Firewall's -    Part 1 | Part 2 | Part 3 |