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packet not see on sniffer

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Jan 26th, 2006
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I have a sniffer set up on 2 side of my network, I see the packet leave the workstation on sniffer A, but it never makes it to sniffer b. The server I am monitoring with sniffer B is set for half duplex. my questions is, if the packet is discarded at the port do to a collision, will I see it on the sniffer??

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Richard Burts Thu, 01/26/2006 - 08:01
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I believe that the answer to your question depends on a couple of things, which include where your sniffer is located, and who is dropping the frame due to collision. If the sniffer is on the same segment with the intended receiver and if some device is transmitting onto that segment and detects a collision and drops the frame, then I believe that the Sniffer will not see the frame (since it is probably less then 64 octets and would not have a correct FCS).

Of course in that scenario the station that dropped the frame due to collision should make attempts to retransmit the frame.



Sergey_P.N. Thu, 01/26/2006 - 08:24
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one of the reason: your sniffer B is connected via

one of network switch or group of the switches,

that mean that unicast packet send from workstation

would be switched directly to server, and You will not see this packet in sniffer B.

To determine problem of discarding you could watch statistic on network equipment port, workstation connected to.


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