OSI Security Concern - Page 3
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Thread: OSI Security Concern

  1. #21
    I am talinkg about wiretapping. In most situations there is no reason for it but the spiffy little device negates the security of fiber lines. In most instances fiber can be approached just like any other medium.

    The way to cut into a line that is outlined here is the least expensive option. If the line isn't being multiplexed then it can be done for under $50 if you can borrow someone's cutter.

    Apparently petemcevoy does not know what network sniffing is in the software sense.

    if someone tries to connect to the ring, they need specialist equipment and the ring would be disturbed - it should not go unnoticed.
    This is what my device tries to limit-connection disruption, while still tapping the line.
    Tsk Tsk that \'vB Code is ON\' is really tempting me.. No bad prof.! BAD!
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  2. #22
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    You're a joker prof3ssor, you haven't got a clue.
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  3. #23
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    I might bore you guys, but I'd like to come back to 'Because FDDI is a fibre optic ring, it is impossible to "listen" by detection of magnetic fields and if someone tries to connect to the ring, they need specialist equipment and the ring would be disturbed - it should not go unnoticed' (from http://www.boran.com/security/it10-l...html#Heading18 ). Now, FDDI consist of two REDUNDANT concentric rings, meaning if one ring (the primary) goes down, the other (the secundary) takes it over. Correct me if I'm wrong, but I don't think you, as a user of that network, would notice that... Of course your administrator would notice it, but it could be too late by that time...
    And Prof3ssor, is this the kind of multiplexing you were talking about? Just curious
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  4. #24
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    i return..

    sorry for my absence from this thread i started.

    physical tapping of fiber optics? not impossible, but to the utmost impractical and certainly there exists a multitude of much easier ways for sniffing a network or individual host ( trojans, modification of routing tables, modification of routers and/or switches, etc). That, at least, is my input.

    --
    So, to further the original intent of my discussion, i move on>

    It came to my attention after some time of thought to ask anyone the following..

    Seeing as the Session Layer (osi layer 5) provides a virtual data stream to the transport layer (osi layer 4) from the Higher levels, data, after being sent below the presentation layer (osi layer 6), that originates @ the Application layer, may not be modified. Like wise, on a recieving system, data that is coming up the stack may not be modified UNTIL it has been 'unpacked' by the mid layers and sent on to the higher layers. This is @ least my assumption. Can anyone else add to this statement? (disprove, add, or approve).

    Inquiry #2: If data is to be neither encoded, encrypted, nor compressed, does it still pass through the presentation layer, under some type of 'null' flag or something?

    OverandOut.
    comJo
    OverandOut.
    ~comJo

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  5. #25
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    Thumbs up my i joined..?

    i need more detailed source so please send me a data about OSI Security maybe i can arraged it to be book for us...
    are any body agree
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  6. #26
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    Re: i return..

    Originally posted by comJo

    Inquiry #2: If data is to be neither encoded, encrypted, nor compressed, does it still pass through the presentation layer, under some type of 'null' flag or something?
    OSI layers are "theorical" (hence the OSI "Model" appellation), it's up to the developpers to decide what layers they will implement depending on the purpos of the stack/application... So no, it isn't passed up to the next layer with a "null flag", since that next "unused" layer just doesn't exist...

    For example, you could write a really basic chat program where you exchange text character by character over a tcp connection. In this example you would use the 4 layers already implemented in the tcp/ip stack (Pysical, data link, network, transport) and would go right to the application layer ie: where your program takes the input from the tcp socket and prints it to the screen.

    Hope this helps..

    Ammo
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  7. #27
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    Talking Duh, encryption at layer 3.

    I don't know why you guyz decided most encryption is done at layer 6?.
    Most modern (Checkpoint, Mircosoft, IPsec) VPN's encrypt at layer 3 or 4 (FWZ, IKE, SKIP) which is as low as you can go on a routed/natted network obviosly. as for Wireless Encryption, 802.11b does come with 40 or 128 wep encryption (which would be Layer 2 ).
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