Updated: 2021/Apr/14

TRACEROUTE6(8)              System Manager's Manual             TRACEROUTE6(8)

     traceroute6 - print the route IPv6 packets will take to the destination

     traceroute6 [-adIlnrv] [-A as_server] [-f firsthop] [-m hoplimit]
                 [-p port] [-q probes] [-s src] [-w waittime] target [datalen]

     traceroute6 uses the IPv6 protocol hop limit field to elicit an ICMPv6
     TIME_EXCEEDED response from each gateway along the path to some host.

     The only mandatory parameter is the destination host name or IPv6
     address.  The default probe datagram carries 12 bytes of payload, in
     addition to the IPv6 header.  The size of the payload can be specified by
     giving a length (in bytes) after the destination host name.

     Other options are:

     -A      Turn on AS# lookups and use the given server instead of the

     -a      Turn on AS# lookups for each hop encountered.

     -d      Turn on socket-level debugging.

     -f firsthop
             Specify how many hops to skip in trace.

     -I      Use ICMP6 ECHO instead of UDP datagrams.

     -l      Print both host hostnames and numeric addresses.  Normally
             traceroute6 prints only hostnames if -n is not specified, and
             only numeric addresses if -n is specified.

     -m hoplimit
             Specify maximum hoplimit, up to 255.  The default is 30 hops.

     -n      Do not resolve numeric address to hostname.

     -p port
             Set the base UDP port number use in probes to port.  The default
             is 33434.  traceroute6 hopes that nothing is listening on UDP
             ports base to base + nhops - 1 at the destination host (so an
             ICMPv6 PORT_UNREACHABLE message will be returned to terminate the
             route tracing).  If something is listening on a port in the
             default range, this option can be used to pick an unused port

     -q probes
             Set the number of probe packets sent per hop count to probes.  By
             default, traceroute6 sends three probe packets.

     -r      Bypass the normal routing tables and send directly to a host on
             an attached network.  If the host is not on a directly-attached
             network, an error is returned.  This option can be used to send
             probes to a local host through an interface that has no route
             through it (e.g., after the interface was dropped by route6d(8)).

     -s src  Use the IPv6 address, src, as the source address in outgoing
             probe packets.

     -v      Be verbose.  Received ICMPv6 packets other than TIME_EXCEEDED and
             UNREACHABLEs are listed.

     -w waittime
             Use waittime as the delay in seconds, between probes.  The
             default is 5 seconds.

     This program prints the route to the given destination and the round-trip
     time to each gateway, in the same manner as traceroute.

     Here is a list of possible annotations after the round-trip time for each

           !N      Destination Unreachable - No Route to Host.

           !X      Destination Unreachable - Administratively Prohibited.

           !S      Destination Unreachable - Not a Neighbour.

           !H      Destination Unreachable - Address Unreachable.

           !       This is printed if the hop limit is <= 1 on a port
                   unreachable message.  This means that the packet got to the
                   destination, but that the reply had a hop limit that was
                   just large enough to allow it to get back to the source of
                   the traceroute6.  This was more interesting in the IPv4
                   case, where some IP stack bugs could be identified by this

     The traceroute6 utility exits 0 on success, and >0 if an error occurs.

     ping(8), ping6(8), traceroute(8)

     The traceroute6 command first appeared in WIDE hydrangea IPv6 protocol
     stack kit.

NetBSD 9.99                     April 23, 2018                     NetBSD 9.99