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Felkor_29336's avatar
Felkor_29336
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Feb 13, 2014

Run tcpdump regarding a match in a log file

Hello !

 

I'm looking for your help. I'm searching for a script which I have used onto a F5 some years ago. It was a script present on the F5 OS, not a specific script added manualy (in a v10.x version as far as I remember).

 

The goal of this script is to run a tcpdump during for a certain number of packets. When this number of packets is exceeded, the script will run automatically a new tcpdump, and check on a specified log file if there was a specific match. If a specific log was generated, the pcap file is conserved, if not, deleted.

 

This script was especially helpfull to be able to perform the capture of random events.

 

I have a random issue here, and I need this tool to be able to take a packet capture this way... however, even after grinding 2 hours in my mails, I wasn't able to find out the mail from F5 giving me the procedure and/or the name of the script !

 

If anyone have more informations for me, it would be great !

 

4 Replies

  • You should be able to login to F5's support portal and review all of your old support cases with all of the notes. Perhaps you will find it there?

     

  • Most certainly yes, but there is something like few hundreds of cases, so it's not that easy with only keywords like tcpdump or script ;)

     

  • BinaryCanary_19's avatar
    BinaryCanary_19
    Historic F5 Account

    I think you're referring to:

    /usr/share/ts/bin/find_error.pl

    It's a Perl script. Hopefully, you can read it and understand how to use it. I've never used it before myself, and I hate perl syntax 🙂

  • YES ! Thank you a lot, that's it. Very usefull script 🙂

    For anyone who is asking, this is the manual of the script and how to use it :

    USAGE:
    ./find_error.pl 
    

    Mandatory arguments:

    -t, --token='Token'
        the token you are searching for
    
    -l, --log_file='Log File'
        fullpath/filename of log file to use for logging
    
    -p, --packet_num='Packet Number'
        the number of the packets to dump
    
    -o, --output_file='Output File'
        fullpath/filename of the output file to use
    

    Optional arguments:

    --zip='zip tar file'
        to zip the final tar file
    
    --nozip='do not zip tar file'
        not to zip the final tar file
    
    -e, --expression='filter expression'
        filtering expression for tcpdump
    
    -i, --interface='Interface'
        Default: 0.0
    
    -s, --snap='Snap length'
        Default: 0
    
    --nnn='use nnn to increasing amounts of internal debugging information appended to the end of each packet'
        Default: nnn
    
    -h, --help='help'
        issue this help message.