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PORTS

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PORTS

qamarhussain2003
Can anyone please explain to me what a tcp/ip port is. I mean can we see it or is it a virtual concept?
how can i create one at home and why is the https port always 4444
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    Zen37

    TCP (or UDP) ports are virtual, not physical.

    The concept of TCP port comes from the fact that a PC can maintain multiple conversations with multiple devices, there's the servers, the printers, the internet, etc.

    In order for the PC to keep up with which bits of information goes with which conversation, it uses TCP ports (among others). The actual https port is TCP 445. If yours is 4444, i figure you are using a proxy that is set to listen to https conversation on that port. Http is port 80, telnet is port 23 etc. server are setup to listen for conversations on specific ports. That also tells then what the conversation request is for.

    Lets set an example.

    You want to browse www.msn.com. In order to simplify the situation, lets say there is no proxy or firewall in the path of communication. Your PC will generate a communication with a random TCP port as the source. Lets say port TCP 35556 with a destination of www.msn.com on port 80. The server of msn.com listens for conversations on port 80 and receive your request for its web page. It answers back to your machine by generating a communication from port 80 to your PC's IP address port 35556. This tells your PC that what it is receiving is the answer to the request it posted from port 35556 and shows you the results on your screen. This occurs in milliseconds.

    I hope this clears up things. Feel free to ask more is you wish.

  • +
    0 Votes
    Zen37

    TCP (or UDP) ports are virtual, not physical.

    The concept of TCP port comes from the fact that a PC can maintain multiple conversations with multiple devices, there's the servers, the printers, the internet, etc.

    In order for the PC to keep up with which bits of information goes with which conversation, it uses TCP ports (among others). The actual https port is TCP 445. If yours is 4444, i figure you are using a proxy that is set to listen to https conversation on that port. Http is port 80, telnet is port 23 etc. server are setup to listen for conversations on specific ports. That also tells then what the conversation request is for.

    Lets set an example.

    You want to browse www.msn.com. In order to simplify the situation, lets say there is no proxy or firewall in the path of communication. Your PC will generate a communication with a random TCP port as the source. Lets say port TCP 35556 with a destination of www.msn.com on port 80. The server of msn.com listens for conversations on port 80 and receive your request for its web page. It answers back to your machine by generating a communication from port 80 to your PC's IP address port 35556. This tells your PC that what it is receiving is the answer to the request it posted from port 35556 and shows you the results on your screen. This occurs in milliseconds.

    I hope this clears up things. Feel free to ask more is you wish.