Hacking: TCP/IP
The last click Issue 1
Given the importance of the internet in hacking, it can't hurt to understand a little about how it works. TCP/IP is most often used for process communication between a server and one (or more) clients. The different processes communicate through a protocol. Usually, several protocols are involved at different levels for the establishment of a communication.
Each protocol has a specific function (data addressing, error checking, data validity checking, etc.).
TCP/IP is the abbreviation for Transmission protocol Control/Internet Protocol. TCP/IP is a set of protocols and sub-protocols organized in layers (hence the name TCP/IP stack).
TCP is one protocol and IP is another. These are the most important ones, but there are many others grouped under the name TCP/IP.
The layers of TCP/IP are not well defined, but we can distinguish 4 main ones:
- The network layer which allows access to a network by managing the network cards and the connection protocols (e.g. the Point to Point Protocol -PPP- used for connections on the Common Telephone Network -RTC- by modem).
- The Internet layer which allows the addressing of machines by the IP protocol (IP addresses) on a local network or public network.
- The transport layer which allows the routing of data, the protocols used are TCP and UDP, many machine ports use UDP, but UDP is less reliable than TCP because it does not check the reception.
- The application layer uses the largest number of protocols (see table below).
Sometimes data is partially lost or damaged. However, errors can be detected and the transmission is reset by the server.
TCP uses flow control and sends data in packets with several layers of information (envelopes, etc.). Pinging consists of sending packets of a certain size and determines the response time of the remote computer.
Here is a table of the main ports used in TCP/IP.
The Internet is therefore largely based on TCP/IP, most of whose sub-protocols cannot be used directly by the user.
Well, I didn't say everything, but it's useless to fill your head. That should be enough for now. I'll talk about the different processes and functions of ports in the next issue.
-= Shin =-
