how does IP logging and gagging work?

[jeremy23_2002]

Hello guys, My question is when I post a thread or topic on this forum is my IP address logged and taken down into some sort of database?

I'm not paranoid but rather interested how a website identifies and perhaps stops a certain computer from accessing that website.

For ex. Say I'm the admin. of this forum , Do I have the right to see every computers IP address that connects to this server? And how would I able to block that person from being able to visit this website if I deemed it justifiable?

I just don't see how it's possible to gagg a certain computer say if they change their username and are connecting through a router with IP spoofing enabled. Wouldn't this server just see the IP address of the router and not the nodes behind it? Becuase the router servs as a DHCP server and Assigns IP addresses dynamically how can the server block those computers?

Perhaps I need to pick up a book on Basic Internet Protocol theory, Thank you for helping in advance. -Jeremy

[Ghost_Hacker]

IP spoofing isn't the right term to use. Ip spoofing is when you use the IP address of another computer. In your case this isn't happening, what is happing is that the router is acting as a proxy for your computer. In other words it takes your ip packets and "resigns" them as it's own.

A little background......


Every time you talk to another computer on the internet you included your IP address and the ip address of the computer you wish to talk to. (think of it as a letter with the address of the reciever and the return address of the sender.) The receiving computer knows who sent the "letter" by the return address included and so can send another letter (packet) back .IP spoofing is when you place the wrong return address on the packet and so the receiving computer is fooled into thinking it's communicating with a computer that it's not. The problem with ip spoofing is that the receiving computer will send all return packets to the spoofed address so the spoofer has no way of know what those return packets say. ( Since the return packets aren't address to the spoofer .He whould need to be "in the line of sight" so that he could sniff the packets off the wire and read their contents. In most cases the spoofer simply can't see what is happening. He's shooting blind.)


In your case the router simply replaces your address with it's own and keep track of that in an internal table. The receiving computer sends all return packets to the router which then sends then back to you.


It is very easy for any computer to filter a packet based on the either of the addresses included and make desisions to accept or reject the packet.
The filter could be on the whole address or simply parts of it. (in other words you can filter on just one computer or a whole network) This is one way a web site can bar someone.

Anyone can read the contents of those IP packets. This information and much more isn't keep secret from anyone. Someone sniffing your network communications could open and read your IP packets. This is why web sites use "secure" channels ( the little lock that appears whenever you enter you credit card info) to encrypt their packets so that only the sender and receiver can open the packet and read the contents.


Hope this helps http://www.PCGuide.com/ubb/smile.gif



[This message has been edited by Ghost_Hacker (edited 04-06-2002).]

[jeremy23_2002]

Yeah that's very helpful. Thank you! One question though. Does my router have a unique specific IP address assigned to it at the hardware level or can I specify what IP address my router shows to the internet?

Or does my router obtain it's IP address from my ISP? and if so is that IP address static? meaning is it always the same? That's where I'm lost how can a website block a computer/node from accessing their services if their IP address is differn't from the one they were using when they got blocked?

I'm on AT&T Cable and I believe they assign Static IP address but I'm not exzactly sure. So If I had Dynamic IP address wouldn't that mean a website couldn't block me becuase my address is never the same. Don't worry I'm not a malicious harm doer I'm just trying to figure out the networking aspect of Data Transfer. Very interesting. Thanks agian

[Ghost_Hacker]

Does my router have a unique specific IP address assigned to it at the hardware level or can I specify what IP address my router shows to the internet?


Yes you can tell a device what it address is. IP addresses dont exist at the hardware level, so you or your ISP can change them at anytime. MAC address however do exist at the hardware level and on most devices can't be changed.( noone filters based on MAC address becase a Packet get this information changed as it passes thur different network interfaces.)

So If I had Dynamic IP address wouldn't that mean a website couldn't block me becuase my address is never the same.


Your right they couldn't unless they where filtering on only part of the ip address. (IE: on the network address rather than the host address)

Hope this helps http://www.PCGuide.com/ubb/smile.gif