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

NAME
     traceroute6 – print the route IPv6 packets will take to a network node

SYNOPSIS
     traceroute6 [-adeEIlnNrTUv] [-f firsthop] [-g gateway] [-m hoplimit]
                 [-p port] [-q probes] [-s src] [-t tclass] [-w waittime]
                 target [datalen]

DESCRIPTION
     The traceroute6 utility 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.

     TCP probes have no payload and the datalen parameter is ignored for TCP.

     Other options are:

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

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

     -d      Debug mode.

     -e      Firewall evasion mode.  Use fixed destination ports for UDP and
             TCP probes.  The destination port does NOT increment with each
             packet sent.

     -E      Detect ECN bleaching.  Set the IPTOS_ECN_ECT1 bit and report if
             that value has been bleached or mangled.

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

     -g gateway
             Specify intermediate gateway ( traceroute6 uses routing header).

     -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.

     -N      Use a packet with no upper layer header for the probes, instead
             of UDP datagrams.

     -p port
             Set UDP port number to port.

     -q probes
             Set the number of probe per hop count to probes.

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

     -s src  Src specifies the source IPv6 address to be used.

     -t tclass
             tclass specifies the traffic class used when sending probe
             packets.  The value must be a decimal integer in the range 0 to
             255.  The default is 0.

     -T      Use TCP segments for the probes.

     -U      Use UDP datagrams for the probes.  This is the default.

     -v      Be verbose.

     -w waittime
             Specify the delay time between probes.

     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
     gateway:

           !N      Destination Unreachable - No Route to Host.

           !P      Destination Unreachable - Administratively Prohibited.

           !S      Destination Unreachable - Not a Neighbour.

           !A      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
                   behaviour.

RETURN VALUES
     The traceroute6 utility will exit with 0 on success, and non-zero on
     errors.

SEE ALSO
     ping(8), ping6(8), traceroute(8)

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

macOS 15.2                       May 17, 1998                       macOS 15.2