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.Dd October 25, 2023 31.Dt TRACEROUTE6 8 32.Os 33.\" 34.Sh NAME 35.Nm traceroute6 36.Nd "print the route IPv6 packets will take to a network node" 37.\" 38.Sh SYNOPSIS 39.Nm 40.Bk -words 41.Op Fl adEIlnNrSTUv 42.Ek 43.Bk -words 44.Op Fl f Ar firsthop 45.Ek 46.Bk -words 47.Op Fl g Ar gateway 48.Ek 49.Bk -words 50.Op Fl m Ar hoplimit 51.Ek 52.Bk -words 53.Op Fl p Ar port 54.Ek 55.Bk -words 56.Op Fl q Ar probes 57.Ek 58.Bk -words 59.Op Fl s Ar src 60.Ek 61.Bk -words 62.Op Fl t Ar tclass 63.Ek 64.Bk -words 65.Op Fl w Ar waittime 66.Ek 67.Bk -words 68.Op Fl A Ar as_server 69.Ek 70.Bk -words 71.Ar target 72.Op Ar datalen 73.Ek 74.\" 75.Sh DESCRIPTION 76The 77.Nm 78utility 79uses the IPv6 protocol hop limit field to elicit an ICMPv6 TIME_EXCEEDED 80response from each gateway along the path to some host. 81.Pp 82The only mandatory parameter is the destination host name or IPv6 address. 83The default probe datagram carries 20 bytes of payload, 84in addition to the IPv6 header. 85The size of the payload can be specified by giving a length 86(in bytes) 87after the destination host name. 88.Pp 89Other options are: 90.Bl -tag -width Ds 91.It Fl a 92Turn on AS# lookups for each hop encountered. 93.It Fl A Ar as_server 94Turn on AS# lookups and use the given server instead of the default. 95.It Fl d 96Debug mode. 97.It Fl E 98Detect ECN bleaching. 99Set the 100.Em IPTOS_ECN_ECT1 101Explicit Congestion Notification (ECN) bits 102.Pq Dv 01 , 103and report if the hop has bleached 104.Pq Dv 00 105or mangled 106.Pq Dv 10 107them, or if it is experiencing congestion 108.Pq Dv 11 . 109Otherwise, report that it passed the bits appropriately. 110If 111.Fl t 112is also specified, the corresponding ECN bits will be replaced. 113.It Fl f Ar firsthop 114Specify how many hops to skip in trace. 115.It Fl g Ar gateway 116Specify intermediate gateway. 117Please note that 118.Nm 119tries to use routing headers. 120.It Fl I 121Use ICMP6 ECHO instead of UDP datagrams. 122.It Fl l 123Print both host hostnames and numeric addresses. 124Normally 125.Nm 126prints only hostnames if 127.Fl n 128is not specified, and only numeric addresses if 129.Fl n 130is specified. 131.It Fl m Ar hoplimit 132Specify maximum hoplimit, up to 255. 133The default is the value of the 134.Va net.inet6.ip6.hlim 135.Xr sysctl 8 136(the same default used for TCP connections). 137.It Fl n 138Do not resolve numeric address to hostname. 139.It Fl N 140Use a packet with no upper layer header for the probes, 141instead of UDP datagrams. 142.It Fl p Ar port 143Set SCTP/TCP/UDP port number to 144.Ar port . 145.It Fl q Ar probes 146Set the number of probe per hop count to 147.Ar probes . 148.It Fl r 149Bypass the normal routing tables and send directly to a host 150on an attached network. 151If the host is not on a directly-connected network, 152an error is returned. 153This option corresponds to the 154.Dv SO_DONTROUTE 155socket option; 156it can be used to ping a local host through an interface 157that has no route through it 158(e.g., after the interface was dropped by a routing daemon). 159.It Fl s Ar src 160.Ar Src 161specifies the source IPv6 address to be used. 162.It Fl S 163Use SCTP packets for the probes. 164The size of probe packets must be a multiple of 4. 165If 166.Ar datalen 167is up to 28, probe packets consist of a SHUTDOWN-ACK chunk possibly bundled 168with a PAD chunk. 169For larger probe packets, an INIT chunk is used. 170.It Fl t Ar tclass 171.Ar tclass 172specifies the 173.Em traffic class 174used when sending probe packets. 175The value must be a decimal integer in the range 0 to 255. 176The default is 0. 177.It Fl T 178Use TCP segments for the probes. 179.It Fl U 180Use UDP datagrams for the probes. 181This is the default. 182.It Fl v 183Be verbose. 184.It Fl w Ar waittime 185Specify the delay time between probes. 186.El 187.Pp 188This program prints the route to the given destination and the round-trip 189time to each gateway, in the same manner as traceroute. 190.Pp 191Here is a list of possible annotations after the round-trip time for each gateway: 192.Bl -hang -offset indent 193.It !N 194Destination Unreachable - No Route to Host. 195.It !P 196Destination Unreachable - Administratively Prohibited. 197.It !S 198Destination Unreachable - Not a Neighbour. 199.It !A 200Destination Unreachable - Address Unreachable. 201.It !H 202Parameter Problem - Unrecognized Next Header Type. 203.It !\& 204This is printed if the hop limit is <= 1 on a port unreachable message. 205This means that the packet got to the destination, 206but that the reply had a hop limit that was just large enough to 207allow it to get back to the source of the traceroute6. 208This was more interesting in the IPv4 case, 209where some IP stack bugs could be identified by this behaviour. 210.El 211.\" 212.Sh EXIT STATUS 213The 214.Nm 215utility will exit with 0 on success, and non-zero on errors. 216.\" 217.Sh SEE ALSO 218.Xr ping 8 , 219.Xr traceroute 8 220.\" 221.Sh HISTORY 222The 223.Nm 224utility first appeared in WIDE hydrangea IPv6 protocol stack kit. 225