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brianokelly_119's avatar
brianokelly_119
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Nov 18, 2010

tcpdump raw packet capture

Does anyone know how to perform a raw packet capture using tcpdump? I have found multiple answers online but none seem to work. When I load the capture into wireshark I still see "Packet truncated during capture".

 

2 Replies

  • Hi Brian,

     

     

    The packets are being truncated because the default packet size capture is tiny. You can use -s 1500 or -s 0 on LTM to capture the full packets.

     

     

     

    SOL411: Overview of packet tracing with the tcpdump utility

     

    http://support.f5.com/kb/en-us/solutions/public/0000/400/sol411.html

     

     

    Capturing Packet Data

     

     

    The tcpdump utility provides an option which allows you to specify the amount of each packet to capture.

     

     

    You can use the -s (snarf/snaplen) option to specify the amount of each packet to capture. To capture the entire packet, use a value of 0 (zero). For example:

     

     

    tcpdump -s0 src host 172.16.101.20 and dst port 80

     

     

     

    Aaron