Provided by: libnet-traceroute-perl_1.15-1_all bug


       Net::Traceroute - traceroute(1) functionality in perl


           use Net::Traceroute;
           $tr = Net::Traceroute->new(host => "");
           if($tr->found) {
               my $hops = $tr->hops;
               if($hops > 1) {
                   print "Router was " .
                       $tr->hop_query_host($tr->hops - 1, 0) . "\n";


       This module implements a parser for various traceroute implementations.  At present, it
       can parse most LBL traceroute derivatives used on typical unixes, and the traceroute of
       cisco IOS.  Traceroutes known not to be supported include that of Microsoft Windows and

       This module has two basic modes of operation, one, where it will run traceroute for you,
       and the other where you provide text from previously runing traceroute to parse.


       A new Net::Traceroute object must be created with the new method.  Depending on exactly
       how the constructor is invoked, it may perform some tracing and/or parsing actions
       immediately, or it may return a "template" object that can be used to set parameters for
       several subsequent traceroutes.

       Methods are available for accessing information about a given traceroute attempt.  There
       are also methods that view/modify the options that are passed to the object's constructor.

       To trace a route, UDP packets are sent with a small TTL (time-to-live) field in an attempt
       to get intervening routers to generate ICMP TIME_EXCEEDED messages.


           $obj = Net::Traceroute->new([base_port      => $base_port,]
                                       [debug          => $debuglvl,]
                                       [max_ttl        => $max_ttl,]
                                       [host           => $host,]
                                       [text           => $text,]
                                       [queries        => $queries,]
                                       [query_timeout  => $query_timeout,]
                                       [timeout        => $timeout,]
                                       [source_address => $srcaddr,]
                                       [tos            => $tos,]
                                       [packetlen      => $packetlen,]
                                       [trace_program  => $program,]
                                       [no_fragment    => $nofrag,]
                                       [use_icmp       => $useicmp,]
                                       [use_tcp        => $usetcp,]
           $frob = $obj->clone([options]);

       This is the constructor for a new Net::Traceroute object.  If given "host", it will
       immediately perform the traceroute.  If given "text", it will parse that text as
       traceroute output.

       Given an existing Net::Traceroute object $obj as a template, you can call $obj->clone()
       with the usual constructor parameters.  The same rules apply about defining host; that is,
       traceroute will be run if it is defined, or text will be parsed.  You can always pass
       "host =" undef, text => undef> to clone.

       Possible options are:

       host - A host to traceroute to.  If you don't set this, you get a Traceroute object with
       no traceroute data in it.  The module always uses IP addresses internally and will attempt
       to lookup host names via inet_aton.

       text - Output from a previously run traceroute.  If set, and host isn't, the given text
       will be parsed.

       base_port - Base port number to use for the UDP queries.  Traceroute assumes that nothing
       is listening to port "base_port" to "base_port + (nhops - 1)" where nhops is the number of
       hops required to reach the destination address.  Default is what the system traceroute
       uses (normally 33434).  "Traceroute"'s "-p" option.

       debuglvl - A number indicating how verbose debug information should be.  Please include
       debug=>9 output in bug reports.

       max_ttl - Maximum number of hops to try before giving up.  Default is what the system
       traceroute uses (normally 30).  "Traceroute"'s "-m" option.

       queries - Number of times to send a query for a given hop.  Defaults to whatever the
       system traceroute uses (3 for most traceroutes).  "Traceroute"'s "-q" option.

       query_timeout - How many seconds to wait for a response to each query sent.  Uses the
       system traceroute's default value of 5 if unspecified.  "Traceroute"'s "-w" option.

       timeout - Maximum time, in seconds, to wait for the traceroute to complete.  If not
       specified, the traceroute will not return until the host has been reached, or traceroute
       counts to infinity ("max_ttl" * "queries" * "query_timeout").  Note that this option is
       implemented by Net::Traceroute, not the underlying traceroute command.

       source_address - Select the source address that traceroute wil use.

       tos - Specify a ToS value for traceroute to use.

       packetlen - Length of packets to use.  Traceroute tries to make the IP packet exactly this

       trace_program - Name of the traceroute program.  Defaults to traceroute.  You can pass
       traceroute6 to do IPv6 traceroutes.

       no_fragment - Set the IP don't fragment bit.  Some traceroute programs will perform path
       mtu discovery with this option.

       use_icmp - Request that traceroute perform probes with ICMP echo packets, rather than UDP.

       use_tcp - Request that traceoute perform probes with TCP SYNs.


           Run system traceroute, and parse the results.  Will fill in the rest of the object for
           informational queries.

           Parse the previously provided "text", filling in the rest of the object for queries.

           Returns a list of arguments that traceroute will be invoked with.  For debugging
           and/or overriding by subclasses.

   Controlling traceroute invocation
       Each of these methods return the current value of the option specified by the
       corresponding constructor option.  They will set the object's instance variable to the
       given value if one is provided.

       Changing an instance variable will only affect newly performed traceroutes.  Setting a
       different value on a traceroute object that has already performed a trace has no effect.

       See the constructor documentation for information about methods that aren't documented


   Obtaining information about a Trace
       These methods return information about a traceroute that has already been performed.

       Any of the methods in this section that return a count of something or want an Nth type
       count to identify something employ one based counting.

           Returns the status of a given traceroute object.  One of TRACEROUTE_OK,
           TRACEROUTE_TIMEOUT, or TRACEROUTE_UNKNOWN (each defined as an integer).  TRACEROUTE_OK
           will only be returned if the host was actually reachable.

           Attempt to return 1 if the host was found, undef otherwise.  This test is a poor
           heuristic, and will frequently give wrong answers.

           If your traceroute supports MTU discovery, this method will return the MTU in some
           circumstances.  You must set no_fragment, and must use a packetlen larger than the
           path mtu for this to be set.

           Returns the number of hops that it took to reach the host.

           Returns the number of queries that were sent for a given hop.  This should normally be
           the same for every query.

       hop_query_stat(HOP, QUERY)
           Return the status of the given HOP's QUERY.  The return status can be one of the
           following (each of these is actually an integer constant function defined in
           Net::Traceroute's export list):

           QUERY can be zero, in which case the first successful query will be returned.

               Reached the host, no problems.

               This query timed out.

               Your guess is as good as mine.  Shouldn't happen too often.

               This hop returned an ICMP Network Unreachable.

               This hop returned an ICMP Host Unreachable.

               This hop returned an ICMP Protocol unreachable.

               Use in cisco and traceroute6 parsing.  In cisco, "!U", in traceroute6, a "!".

               This hop returned an ICMP6 address unreachable.

               Indicates that you can't reach this host without fragmenting your packet further.
               Shouldn't happen in regular use.

               A source routed packet was rejected for some reason.  Shouldn't happen.

               A firewall or similar device has decreed that your traffic is disallowed by
               administrative action.  Suspect sheer, raving paranoia.

               The destination machine appears to exhibit the 4.[23]BSD time exceeded bug.

               Some machine has generated an ICMP Source Quench message, asking you to slow down.

               "User interrupted test".  Cisco's traceroute does this.  Its unclear how to
               produce it.

       hop_query_host(HOP, QUERY)
           Return the dotted quad IP address of the host that responded to HOP's QUERY.

           QUERY can be zero, in which case the first successful query will be returned.

       hop_query_time(HOP, QUERY)
           Return the round trip time associated with the given HOP's query.  If your system's
           traceroute supports fractional second timing, so will Net::Traceroute.

           QUERY can be zero, in which case the first successful query will be returned.


       Net::Traceroute Versions before 1.04 used new to clone objects.  This has been deprecated
       in favor of the clone() method.

       If you have code of the form:

        my $template = Net::Traceroute->new();
        my $tr = $template->new(host => "localhost");

       You need to change the $template->new to $template->clone.

       This behavior was changed because it interfered with subclassing.


       Net::Traceroute parses the output of the system traceroute command.  As such, it may not
       work on your system.  Support for more traceroute outputs (e.g. Windows, HPUX) could be
       done, although currently the code assumes there is "One true traceroute".

       The actual functionality of traceroute could also be implemented natively in perl or
       linked in from a C library.

       Versions prior to 1.04 had some interface issues for subclassing.  These issues have been
       addressed, but required a public interface change.  If you were relying on the behavior of
       new to clone existing objects, your code needs to be fixed.




       Daniel Hagerty <>


       Copyright 1998, 1999 Massachusetts Institute of Technology Copyright 2000, 2001 Daniel

       Permission to use, copy, modify, distribute, and sell this software and its documentation
       for any purpose is hereby granted without fee, provided that the above copyright notice
       appear in all copies and that both that copyright notice and this permission notice appear
       in supporting documentation, and that the name of M.I.T. not be used in advertising or
       publicity pertaining to distribution of the software without specific, written prior
       permission.  M.I.T. makes no representations about the suitability of this software for
       any purpose.  It is provided "as is" without express or implied warranty.