1.\" $KAME: ping6.8,v 1.43 2001/06/28 06:54:29 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: src/sbin/ping6/ping6.8,v 1.3.2.12 2003/02/24 00:56:42 trhodes Exp $ 31.\" 32.Dd April 21, 2018 33.Dt PING6 8 34.Os 35.Sh NAME 36.Nm ping6 37.Nd send 38.Tn ICMPv6 ECHO_REQUEST 39packets to network hosts 40.Sh SYNOPSIS 41.Nm 42.Op Fl dfHnNqRtvwW 43.Bk -words 44.Op Fl a Ar addrtype 45.Ek 46.Bk -words 47.Op Fl b Ar bufsiz 48.Ek 49.Bk -words 50.Op Fl c Ar count 51.Ek 52.Bk -words 53.Op Fl h Ar hoplimit 54.Ek 55.Bk -words 56.Op Fl I Ar interface 57.Ek 58.Bk -words 59.Op Fl i Ar wait 60.Ek 61.Bk -words 62.Op Fl l Ar preload 63.Ek 64.Bk -words 65.Op Fl p Ar pattern 66.Ek 67.Bk -words 68.Op Fl S Ar sourceaddr 69.Ek 70.Bk -words 71.Op Fl s Ar packetsize 72.Ek 73.Bk -words 74.Op Ar hops...\& 75.Ek 76.Bk -words 77.Ar host 78.Ek 79.Sh DESCRIPTION 80The 81.Nm 82utility uses the 83.Tn ICMPv6 84protocol's mandatory 85.Tn ICMP6_ECHO_REQUEST 86datagram to elicit an 87.Tn ICMP6_ECHO_REPLY 88from a host or gateway. 89.Tn ICMP6_ECHO_REQUEST 90datagrams (``pings'') have an IPv6 header, 91and 92.Tn ICMPv6 93header formatted as documented in RFC 2463. 94The options are as follows: 95.Bl -tag -width Ds 96.It Fl a Ar addrtype 97Generate ICMPv6 Node Information Node Addresses query, rather than echo-request. 98.Ar addrtype 99must be a string constructed of the following characters. 100.Bl -tag -width Ds -compact 101.It Ic a 102requests all the responder's unicast addresses. 103If the character is omitted, 104only those addresses which belong to the interface which has the 105responder's address are requests. 106.It Ic c 107requests responder's IPv4-compatible and IPv4-mapped addresses. 108.It Ic g 109requests responder's global-scope addresses. 110.It Ic s 111requests responder's site-local addresses. 112.It Ic l 113requests responder's link-local addresses. 114.It Ic A 115requests responder's anycast addresses. 116Without this character, the responder will return unicast addresses only. 117With this character, the responder will return anycast addresses only. 118Note that the specification does not specify how to get responder's 119anycast addresses. 120This is an experimental option. 121.El 122.It Fl b Ar bufsiz 123Set socket buffer size. 124.It Fl c Ar count 125Stop after sending 126(and receiving) 127.Ar count 128.Tn ECHO_RESPONSE 129packets. 130.It Fl d 131Set the 132.Dv SO_DEBUG 133option on the socket being used. 134.It Fl f 135Flood ping. 136Outputs packets as fast as they come back or one hundred times per second, 137whichever is more. 138For every 139.Tn ECHO_REQUEST 140sent a period 141.Dq .\& 142is printed, while for every 143.Tn ECHO_REPLY 144received a backspace is printed. 145This provides a rapid display of how many packets are being dropped. 146Only the super-user may use this option. 147.Bf -emphasis 148This can be very hard on a network and should be used with caution. 149.Ef 150.It Fl H 151Specifies to try reverse-lookup of IPv6 addresses. 152The 153.Nm 154utility does not try reverse-lookup unless the option is specified. 155.It Fl h Ar hoplimit 156Set the IPv6 hoplimit. 157.It Fl I Ar interface 158Source packets with the given interface address. 159This flag applies if the ping destination is a multicast address, 160or link-local/site-local unicast address. 161.It Fl i Ar wait 162Wait 163.Ar wait 164seconds 165.Em between sending each packet . 166The default is to wait for one second between each packet. 167This option is incompatible with the 168.Fl f 169option. 170.It Fl l Ar preload 171If 172.Ar preload 173is specified, 174.Nm 175sends that many packets as fast as possible before falling into its normal 176mode of behavior. 177Only the super-user may use this option. 178.It Fl n 179Numeric output only. 180No attempt will be made to lookup symbolic names from addresses in the reply. 181.It Fl N 182Probe node information multicast group 183.Pq Li ff02::2:xxxx:xxxx . 184.Ar host 185must be string hostname of the target 186(must not be a numeric IPv6 address). 187Node information multicast group will be computed based on given 188.Ar host , 189and will be used as the final destination. 190Since node information multicast group is a link-local multicast group, 191destination link needs to be specified by 192.Fl I 193option. 194.It Fl p Ar pattern 195You may specify up to 16 196.Dq pad 197bytes to fill out the packet you send. 198This is useful for diagnosing data-dependent problems in a network. 199For example, 200.Dq Li \-p ff 201will cause the sent packet to be filled with all 202ones. 203.It Fl q 204Quiet output. 205Nothing is displayed except the summary lines at startup time and 206when finished. 207.It Fl R 208Make the kernel believe that the target 209.Ar host 210(or the first 211.Ar hop 212if you specify 213.Ar hops ) 214is reachable, by injecting upper-layer reachability confirmation hint. 215The option is meaningful only if the target 216.Ar host 217(or the first hop) 218is a neighbor. 219.It Fl S Ar sourceaddr 220Specifies the source address of request packets. 221The source address must be one of the unicast addresses of the sending node. 222If the outgoing interface is specified by the 223.Fl I 224option as well, 225.Ar sourceaddr 226needs to be an address assigned to the specified interface. 227.It Fl s Ar packetsize 228Specifies the number of data bytes to be sent. 229The default is 56, which translates into 64 230.Tn ICMP 231data bytes when combined 232with the 8 bytes of 233.Tn ICMP 234header data. 235You may need to specify 236.Fl b 237as well to extend socket buffer size. 238.It Fl t 239Generate ICMPv6 Node Information supported query types query, 240rather than echo-request. 241.Fl s 242has no effect if 243.Fl t 244is specified. 245.It Fl v 246Verbose output. 247.Tn ICMP 248packets other than 249.Tn ECHO_RESPONSE 250that are received are listed. 251.It Fl w 252Generate ICMPv6 Node Information DNS Name query, rather than echo-request. 253.Fl s 254has no effect if 255.Fl w 256is specified. 257.It Fl W 258Same as 259.Fl w , 260but with old packet format based on 03 draft. 261This option is present for backward compatibility. 262.Fl s 263has no effect if 264.Fl w 265is specified. 266.It Ar hops 267IPv6 addresses for intermediate nodes, 268which will be put into type 0 routing header. 269.It Ar host 270IPv6 address of the final destination node. 271.El 272.Pp 273When using 274.Nm 275for fault isolation, it should first be run on the local host, to verify 276that the local network interface is up and running. 277Then, hosts and gateways further and further away should be 278.Dq pinged . 279Round-trip times and packet loss statistics are computed. 280If duplicate packets are received, they are not included in the packet 281loss calculation, although the round trip time of these packets is used 282in calculating the round-trip time statistics. 283When the specified number of packets have been sent 284(and received) 285or if the program is terminated with a 286.Dv SIGINT , 287a brief summary is displayed, showing the number of packets sent and 288received, and the minimum, mean, maximum, and standard deviation of 289the round-trip times. 290.Pp 291If 292.Nm 293receives a 294.Dv SIGINFO 295(see the 296.Cm status 297argument for 298.Xr stty 1 ) 299signal, the current number of packets sent and received, and the 300minimum, mean, maximum, and standard deviation of the round-trip times 301will be written to the standard output in the same format as the 302standard completion message. 303.Pp 304This program is intended for use in network testing, measurement and 305management. 306Because of the load it can impose on the network, it is unwise to use 307.Nm 308during normal operations or from automated scripts. 309.\" .Sh ICMP PACKET DETAILS 310.\" An IP header without options is 20 bytes. 311.\" An 312.\" .Tn ICMP 313.\" .Tn ECHO_REQUEST 314.\" packet contains an additional 8 bytes worth of 315.\" .Tn ICMP 316.\" header followed by an arbitrary amount of data. 317.\" When a 318.\" .Ar packetsize 319.\" is given, this indicated the size of this extra piece of data 320.\" (the default is 56). 321.\" Thus the amount of data received inside of an IP packet of type 322.\" .Tn ICMP 323.\" .Tn ECHO_REPLY 324.\" will always be 8 bytes more than the requested data space 325.\" (the 326.\" .Tn ICMP 327.\" header). 328.\" .Pp 329.\" If the data space is at least eight bytes large, 330.\" .Nm 331.\" uses the first eight bytes of this space to include a timestamp which 332.\" it uses in the computation of round trip times. 333.\" If less than eight bytes of pad are specified, no round trip times are 334.\" given. 335.Sh DUPLICATE AND DAMAGED PACKETS 336The 337.Nm 338utility will report duplicate and damaged packets. 339Duplicate packets should never occur when pinging a unicast address, 340and seem to be caused by 341inappropriate link-level retransmissions. 342Duplicates may occur in many situations and are rarely 343(if ever) 344a good sign, although the presence of low levels of duplicates may not 345always be cause for alarm. 346Duplicates are expected when pinging a broadcast or multicast address, 347since they are not really duplicates but replies from different hosts 348to the same request. 349.Pp 350Damaged packets are obviously serious cause for alarm and often 351indicate broken hardware somewhere in the 352.Nm 353packet's path 354(in the network or in the hosts). 355.Sh TRYING DIFFERENT DATA PATTERNS 356The 357(inter)network 358layer should never treat packets differently depending on the data 359contained in the data portion. 360Unfortunately, data-dependent problems have been known to sneak into 361networks and remain undetected for long periods of time. 362In many cases the particular pattern that will have problems is something 363that does not have sufficient 364.Dq transitions , 365such as all ones or all zeros, or a pattern right at the edge, such as 366almost all zeros. 367It is not 368necessarily enough to specify a data pattern of all zeros (for example) 369on the command line because the pattern that is of interest is 370at the data link level, and the relationship between what you type and 371what the controllers transmit can be complicated. 372.Pp 373This means that if you have a data-dependent problem you will probably 374have to do a lot of testing to find it. 375If you are lucky, you may manage to find a file that either 376cannot 377be sent across your network or that takes much longer to transfer than 378other similar length files. 379You can then examine this file for repeated patterns that you can test 380using the 381.Fl p 382option of 383.Nm . 384.Sh EXIT STATUS 385The 386.Nm 387utility returns 0 on success (the host is alive), 388and non-zero if the arguments are incorrect or the host is not responding. 389.Sh EXAMPLES 390Normally, 391.Nm 392works just like 393.Xr ping 8 394would work; the following will send ICMPv6 echo request to 395.Li dst.foo.com . 396.Bd -literal -offset indent 397ping6 -n dst.foo.com 398.Ed 399.Pp 400The following will probe hostnames for all nodes on the network link attached to 401.Li wi0 402interface. 403The address 404.Li ff02::1 405is named the link-local all-node multicast address, and the packet would 406reach every node on the network link. 407.Bd -literal -offset indent 408ping6 -w ff02::1%wi0 409.Ed 410.Pp 411The following will probe addresses assigned to the destination node, 412.Li dst.foo.com . 413.Bd -literal -offset indent 414ping6 -a agl dst.foo.com 415.Ed 416.Sh SEE ALSO 417.Xr netstat 1 , 418.Xr icmp6 4 , 419.Xr inet6 4 , 420.Xr ip6 4 , 421.Xr ifconfig 8 , 422.Xr ping 8 , 423.Xr routed 8 , 424.Xr traceroute 8 , 425.Xr traceroute6 8 426.Rs 427.%A A. Conta 428.%A S. Deering 429.%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification" 430.%N RFC 2463 431.%D December 1998 432.Re 433.Rs 434.%A Matt Crawford 435.%T "IPv6 Node Information Queries" 436.%N draft-ietf-ipngwg-icmp-name-lookups-07.txt 437.%D August 2000 438.%O work in progress material 439.Re 440.Sh HISTORY 441The 442.Xr ping 8 443command appeared in 444.Bx 4.3 . 445The 446.Nm 447utility with IPv6 support first appeared in WIDE Hydrangea IPv6 protocol stack 448kit. 449.Pp 450IPv6 support based on the KAME Project 451.Pa ( http://www.kame.net/ ) 452stack was initially integrated into 453.Fx 4.0 454.Sh BUGS 455There have been many discussions on why we separate 456.Nm 457and 458.Xr ping 8 . 459Some people argued that it would be more convenient to uniform the 460ping command for both IPv4 and IPv6. 461The followings are an answer to the request. 462.Pp 463From a developer's point of view: 464since the underling raw sockets API is totally different between IPv4 465and IPv6, we would end up having two types of code base. 466There would actually be less benefit to uniform the two commands 467into a single command from the developer's standpoint. 468.Pp 469From an operator's point of view: unlike ordinary network applications 470like remote login tools, we are usually aware of address family when using 471network management tools. 472We do not just want to know the reachability to the host, but want to know the 473reachability to the host via a particular network protocol such as 474IPv6. 475Thus, even if we had a unified 476.Xr ping 8 477command for both IPv4 and IPv6, we would usually type a 478.Fl 6 479or 480.Fl 4 481option (or something like those) to specify the particular address family. 482This essentially means that we have two different commands. 483