Re: Traceroute Anomaly

From: Chuck Swiger (cswiger_at_mac.com)
Date: 08/20/04

  • Next message: Barney Wolff: "Re: Traceroute Anomaly"
    Date: Fri, 20 Aug 2004 13:20:14 -0400
    To: Gregory Kuhn <freebsd-net@lists.ctch.net>
    
    

    Gregory Kuhn wrote:
    [ ... ]
    > Why can I do a traceroute using the DOS version of traceroute (tracert)
    > to any of my FreeBSD boxes, but I am not able to do so from another
    > FreeBSD box? Furthermore, it is not just from my own boxes that I am
    > unable to do a traceroute. Using the traceroutes listed at
    > www.traceroute.org I again am unable to trace back to my FBSD boxes.

    Different traceroute programs use different protocols; in fact, the BSD
    traceroute supports:

            -P Send packets of specified IP protocol. The currently supported
                   protocols are: UDP, TCP, GRE and ICMP. Other protocols may also
                   be specified (either by name or by number), though traceroute
                   does not implement any special knowledge of their packet for-
                   mats. This option is useful for determining which router along a
                   path may be blocking packets based on IP protocol number. But
                   see BUGS below.

    ...and if you read the rest of the manpage, it will discuss the fact that it
    is fairly common for traceroute to not show the last hop when using protocols
    other than UDP.

    -- 
    -Chuck
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  • Next message: Barney Wolff: "Re: Traceroute Anomaly"

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