1.\" $KAME: traceroute6.8,v 1.10 2004/06/06 12:35:15 suz Exp $ 2.\" 3.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the project nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" $FreeBSD$ 31.\" 32.Dd November 25, 2020 33.Dt TRACEROUTE6 8 34.Os 35.\" 36.Sh NAME 37.Nm traceroute6 38.Nd "print the route IPv6 packets will take to a network node" 39.\" 40.Sh SYNOPSIS 41.Nm 42.Bk -words 43.Op Fl adIlnNrSTUv 44.Ek 45.Bk -words 46.Op Fl f Ar firsthop 47.Ek 48.Bk -words 49.Op Fl g Ar gateway 50.Ek 51.Bk -words 52.Op Fl m Ar hoplimit 53.Ek 54.Bk -words 55.Op Fl p Ar port 56.Ek 57.Bk -words 58.Op Fl q Ar probes 59.Ek 60.Bk -words 61.Op Fl s Ar src 62.Ek 63.Bk -words 64.Op Fl t Ar tclass 65.Ek 66.Bk -words 67.Op Fl w Ar waittime 68.Ek 69.Bk -words 70.Op Fl A Ar as_server 71.Ek 72.Bk -words 73.Ar target 74.Op Ar datalen 75.Ek 76.\" 77.Sh DESCRIPTION 78The 79.Nm 80utility 81uses the IPv6 protocol hop limit field to elicit an ICMPv6 TIME_EXCEEDED 82response from each gateway along the path to some host. 83.Pp 84The only mandatory parameter is the destination host name or IPv6 address. 85The default probe datagram carries 20 bytes of payload, 86in addition to the IPv6 header. 87The size of the payload can be specified by giving a length 88(in bytes) 89after the destination host name. 90.Pp 91Other options are: 92.Bl -tag -width Ds 93.It Fl a 94Turn on AS# lookups for each hop encountered. 95.It Fl A Ar as_server 96Turn on AS# lookups and use the given server instead of the default. 97.It Fl d 98Debug mode. 99.It Fl f Ar firsthop 100Specify how many hops to skip in trace. 101.It Fl g Ar gateway 102Specify intermediate gateway. 103Please note that 104.Nm 105tries to use routing headers. 106.It Fl I 107Use ICMP6 ECHO instead of UDP datagrams. 108.It Fl l 109Print both host hostnames and numeric addresses. 110Normally 111.Nm 112prints only hostnames if 113.Fl n 114is not specified, and only numeric addresses if 115.Fl n 116is specified. 117.It Fl m Ar hoplimit 118Specify maximum hoplimit, up to 255. 119The default is the value of the 120.Va net.inet6.ip6.hlim 121.Xr sysctl 8 122(the same default used for TCP connections). 123.It Fl n 124Do not resolve numeric address to hostname. 125.It Fl N 126Use a packet with no upper layer header for the probes, 127instead of UDP datagrams. 128.It Fl p Ar port 129Set SCTP/TCP/UDP port number to 130.Ar port . 131.It Fl q Ar probes 132Set the number of probe per hop count to 133.Ar probes . 134.It Fl r 135Bypass the normal routing tables and send directly to a host 136on an attached network. 137If the host is not on a directly-connected network, 138an error is returned. 139This option corresponds to the 140.Dv SO_DONTROUTE 141socket option; 142it can be used to ping a local host through an interface 143that has no route through it 144(e.g., after the interface was dropped by a routing daemon). 145.It Fl s Ar src 146.Ar Src 147specifies the source IPv6 address to be used. 148.It Fl S 149Use SCTP packets for the probes. 150The size of probe packets must be a multiple of 4. 151If 152.Ar datalen 153is up to 28, probe packets consist of a SHUTDOWN-ACK chunk possibly bundled 154with a PAD chunk. 155For larger probe packets, an INIT chunk is used. 156.It Fl t Ar tclass 157.Ar tclass 158specifies the 159.Em traffic class 160used when sending probe packets. 161The value must be a decimal integer in the range 0 to 255. 162The default is 0. 163.It Fl T 164Use TCP segments for the probes. 165.It Fl U 166Use UDP datagrams for the probes. 167This is the default. 168.It Fl v 169Be verbose. 170.It Fl w Ar waittime 171Specify the delay time between probes. 172.El 173.Pp 174This program prints the route to the given destination and the round-trip 175time to each gateway, in the same manner as traceroute. 176.Pp 177Here is a list of possible annotations after the round-trip time for each gateway: 178.Bl -hang -offset indent 179.It !N 180Destination Unreachable - No Route to Host. 181.It !P 182Destination Unreachable - Administratively Prohibited. 183.It !S 184Destination Unreachable - Not a Neighbour. 185.It !A 186Destination Unreachable - Address Unreachable. 187.It !H 188Parameter Problem - Unrecognized Next Header Type. 189.It !\& 190This is printed if the hop limit is <= 1 on a port unreachable message. 191This means that the packet got to the destination, 192but that the reply had a hop limit that was just large enough to 193allow it to get back to the source of the traceroute6. 194This was more interesting in the IPv4 case, 195where some IP stack bugs could be identified by this behaviour. 196.El 197.\" 198.Sh EXIT STATUS 199The 200.Nm 201utility will exit with 0 on success, and non-zero on errors. 202.\" 203.Sh SEE ALSO 204.Xr ping 8 , 205.Xr traceroute 8 206.\" 207.Sh HISTORY 208The 209.Nm 210utility first appeared in WIDE hydrangea IPv6 protocol stack kit. 211