Re: Incorrect Linux ARP behavior

From: pedwardat_private
Date: Fri Sep 18 1998 - 19:01:20 PDT

  • Next message: Darren Reed: "stopping "nack" `stealth' scanning."

    >
    > if(ether_header_destination != device_hardware_address) return;
    >
    
    When you place the interface in promiscuous mode (on Linux), this chunk
    of code is exactly what you're bypassing.
    
    It would probably be more accurate to say that the sniffer detector
    simply finds machines that are in promiscuous mode, and exhibit the
    behaviour that ARPs are returned for ETH's not it's own.
    
    You can detect if a box is in promiscuous mode easier if:
    
    Send a packet with the correct IP of the box:odd port, but the wrong ETH
    address.  If you get an RST, the box is in promiscuous mode.  If
    you do not, it's not.
    
    >
    > Seth M. McGann / smmat_private        "Security is making it
    >
    
    --Perry
    
    --
    Perry Harrington        System Software Engineer    zelur xuniL  ()
    http://www.webcom.com  perry.harringtonat_private  Think Blue.  /\
    



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