Thread: Need Help in Unix commands

  1. #1
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    Need Help in Unix commands

    Hello - I have to do these two tasks - could someon help me in Commands or guide me the process to achieve these things.

    1 - Find out the generic format for TCP header options from Request for Comments 793

    2 - Find out how TCP is supposed to respond if a FIN or an RST arrives with a sequence number other than NextByteExpected.

    Earlier I thought with the help of netstat I can figure it out but netstat only shows connection status as Esatblished or connected.

    Please advice.

  2. #2
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    Why are you asking us? The answers you are looking for are in the RFC.

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    I am asking these question here because I have to do the same on the Linux machine. I don't kknow which commands we need to use in Linux to see the generic format of TCP header options.

    Please suggest.

  4. #4
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    Download firefox (use wget, for example), then run firefox and enter Google, then enter RFC 793 in the search for box. Look for a document describing the TCP IP header format.

    The format is not any different for different machines or OS's.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

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    Mat - thanks for the reply. Is there is any command which can be used in Linux as we have to solve this on Linux machine.

    As I understand Firefox is web browser Windows utility.

    Once again thanks for the reply.

  6. #6
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    You mean to describe the RFC 793? As far as I know, it's a document, and it is the same for Linux as for everything else. Firefox is indeed a web-browser, and that's at least how I would find that sort of information if I needed it. Whether you use firefox or some other web-browser is up to you.

    If you really want to make your own life more difficult and not use a web-browser, then perhaps you can write down the link posted above that answers the question, and then use wget to download the document in the link and view the HTML in some text editor. But I don't see the point of it.

    And I certainly do not see the point of discussing "Unix" or "Linux" commands here.

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    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  7. #7
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    Mat - I understood your point. Thanks

    How about "Find out how TCP is supposed to respond if a FIN or an RST arrives with a sequence number other than NextByteExpected."

    Do you have any helpful link or any suggestion for this?

    thanks

  8. #8
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    The answer to that question will be in the RFC as well.

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    I read in the RFC dcument RFC 793 (rfc793) - Transmission Control Protocol - but its not mentioned any where.

    Any thoughts.

  10. #10
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    Try reading page 23 again.

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  11. #11
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    Thanks Mats - I got it.

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