Basic TCP/IP Confusing Me

[imported_Deathray]

The router that came with my ISP, has a firewall built in and offers no way of port forwarding. It is completely locked, the only way of configuring it is remotely through their support, with a fee of $100.

Now I would like to get an understanding of how TCP/IP works in this situation.

It is impossible for me to create a server of any type, web server/IRC/ftp whatever. People cannot connect because the ports cannot be forwarded through the router.

But how is this possible when I am able to access the internet, write in this forum, play a game, whatever. Packets are being sent out obviously,
but what is the difference between me digit'ing a message in MSN, to creating a webserver that will also send HTML to the client accessing my page?

Do you get me?
An explanation about this would be greatly appreciated (:

[PrairieFire]

List of TCP and UDP Port numbers should help answer some of your questions.

[imported_Deathray]

The information I am seeking cannot be found there unfortunately.
This is damn hard to explain lol :b, but I'm trying.

For example: In 2 minutes I will be posting this message to forums.remote-exploit.org, which will be sent through port 80, right?
Now how is this information being sent over port 80, if it is closed on the router!
YES!, manages to explain myself THAT is the mystery that I am really confused about.

[imported_Deathray]

Thinking about this and going to come with a guess.
Is it because the hardware firewall is made so that it is not possible for me to
listen on any port, but any connection to my box made remotely will let me send packets back? But if that hypothesis is correct, how can ... arghhh nevermind .. Really confused :b .. Try answering my last post that should clear things up

[streaker69]

Thinking about this and going to come with a guess.
Is it because the hardware firewall is made so that it is not possible for me to
listen on any port, but any connection to my box made remotely will let me send packets back? But if that hypothesis is correct, how can ... arghhh nevermind .. Really confused :b .. Try answering my last post that should clear things up

I think you might want to read up on NAT and dynamic port allocation.

[imported_Deathray]

Thanks a lot, NAT definitely contains all the answers
to my confusion + this is pretty interesting .

[balding_parrot]

A full understanding of the material intended for the N+ exam wouldn't go a miss either.
Without knowing the material for that exam, you are really going to struggle and end up asking a lot of basic questions that probably won't get answered in the way that you would like, as that kind of knowledge is considered a prerequisite before even attempting to use backtrack.

[imported_wyze]

May be a trivial question / suggestion, but why are you committed to using their router? Why not purchase on that has port forwarding capabilities?

[purehate]

You might laugh at me but this book was extremely helpful to me in learning this subject

[imported_Deathray]

A full understanding of the material intended for the N+ exam wouldn't go a miss either.
Without knowing the material for that exam, you are really going to struggle and end up asking a lot of basic questions that probably won't get answered in the way that you would like, as that kind of knowledge is considered a prerequisite before even attempting to use backtrack.

I am not using backtrack for any purpose other than learning IT security.
It is basically my learning environment and BT's purpose may be a lot more
advanced for me, but I feel it is still the most appropriate OS
for me to learn in.

May be a trivial question / suggestion, but why are you committed to using their router? Why not purchase on that has port forwarding capabilities?

I'm only 17 and unfortunately don't live with my parents. Only in the weekends.
Where I live in the weekdays, there is no way of persuading the system to
use another router/ISP.

You might laugh at me but this book was extremely helpful to me in learning this subject

Seems like this book fit's perfectly for my level. I got a whole lot of practical knowledge of how to get things done, but strongly need the theoretical :b Thanks for the recommendation.