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.\" $DragonFly: src/sbin/ping6/ping6.8,v 1.7 2007/11/23 23:16:36 swildner Exp $ 32.\" 33.Dd May 17, 1998 34.Dt PING6 8 35.Os 36.Sh NAME 37.Nm ping6 38.Nd send 39.Tn ICMPv6 ECHO_REQUEST 40packets to network hosts 41.Sh SYNOPSIS 42.Nm 43.\" without ipsec, or new ipsec 44.Op Fl dfHnNqRtvwW 45.\" old ipsec 46.\" .Op Fl AdEfnNqRtvwW 47.Bk -words 48.Op Fl a Ar addrtype 49.Ek 50.Bk -words 51.Op Fl b Ar bufsiz 52.Ek 53.Bk -words 54.Op Fl c Ar count 55.Ek 56.Bk -words 57.Op Fl h Ar hoplimit 58.Ek 59.Bk -words 60.Op Fl I Ar interface 61.Ek 62.Bk -words 63.Op Fl i Ar wait 64.Ek 65.Bk -words 66.Op Fl l Ar preload 67.Ek 68.Bk -words 69.Op Fl p Ar pattern 70.Ek 71.Bk -words 72.\" new ipsec 73.Op Fl P Ar policy 74.Ek 75.Bk -words 76.Op Fl S Ar sourceaddr 77.Ek 78.Bk -words 79.Op Fl s Ar packetsize 80.Ek 81.Bk -words 82.Op Ar hops...\& 83.Ek 84.Bk -words 85.Ar host 86.Ek 87.Sh DESCRIPTION 88The 89.Nm 90utility uses the 91.Tn ICMPv6 92protocol's mandatory 93.Tn ICMP6_ECHO_REQUEST 94datagram to elicit an 95.Tn ICMP6_ECHO_REPLY 96from a host or gateway. 97.Tn ICMP6_ECHO_REQUEST 98datagrams (``pings'') have an IPv6 header, 99and 100.Tn ICMPv6 101header formatted as documented in RFC 2463. 102The options are as follows: 103.Bl -tag -width Ds 104.\" old ipsec 105.\" .It Fl A 106.\" Enables transport-mode IPsec authentication header 107.\" (experimental). 108.It Fl a Ar addrtype 109Generate ICMPv6 Node Information Node Addresses query, rather than echo-request. 110.Ar addrtype 111must be a string constructed of the following characters. 112.Bl -tag -width Ds -compact 113.It Ic a 114requests all the responder's unicast addresses. 115If the character is omitted, 116only those addresses which belong to the interface which has the 117responder's address are requests. 118.It Ic c 119requests responder's IPv4-compatible and IPv4-mapped addresses. 120.It Ic g 121requests responder's global-scope addresses. 122.It Ic s 123requests responder's site-local addresses. 124.It Ic l 125requests responder's link-local addresses. 126.It Ic A 127requests responder's anycast addresses. 128Without this character, the responder will return unicast addresses only. 129With this character, the responder will return anycast addresses only. 130Note that the specification does not specify how to get responder's 131anycast addresses. 132This is an experimental option. 133.El 134.It Fl b Ar bufsiz 135Set socket buffer size. 136.It Fl c Ar count 137Stop after sending 138(and receiving) 139.Ar count 140.Tn ECHO_RESPONSE 141packets. 142.It Fl d 143Set the 144.Dv SO_DEBUG 145option on the socket being used. 146.\" .It Fl E 147.\" Enables transport-mode IPsec encapsulated security payload 148.\" (experimental). 149.It Fl f 150Flood ping. 151Outputs packets as fast as they come back or one hundred times per second, 152whichever is more. 153For every 154.Tn ECHO_REQUEST 155sent a period 156.Dq .\& 157is printed, while for every 158.Tn ECHO_REPLY 159received a backspace is printed. 160This provides a rapid display of how many packets are being dropped. 161Only the super-user may use this option. 162.Bf -emphasis 163This can be very hard on a network and should be used with caution. 164.Ef 165.It Fl H 166Specifies to try reverse-lookup of IPv6 addresses. 167The 168.Nm 169utility does not try reverse-lookup unless the option is specified. 170.It Fl h Ar hoplimit 171Set the IPv6 hoplimit. 172.It Fl I Ar interface 173Source packets with the given interface address. 174This flag applies if the ping destination is a multicast address, 175or link-local/site-local unicast address. 176.It Fl i Ar wait 177Wait 178.Ar wait 179seconds 180.Em between sending each packet . 181The default is to wait for one second between each packet. 182This option is incompatible with the 183.Fl f 184option. 185.It Fl l Ar preload 186If 187.Ar preload 188is specified, 189.Nm 190sends that many packets as fast as possible before falling into its normal 191mode of behavior. 192Only the super-user may use this option. 193.It Fl n 194Numeric output only. 195No attempt will be made to lookup symbolic names from addresses in the reply. 196.It Fl N 197Probe node information multicast group 198.Pq Li ff02::2:xxxx:xxxx . 199.Ar host 200must be string hostname of the target 201(must not be a numeric IPv6 address). 202Node information multicast group will be computed based on given 203.Ar host , 204and will be used as the final destination. 205Since node information multicast group is a link-local multicast group, 206destination link needs to be specified by 207.Fl I 208option. 209.It Fl p Ar pattern 210You may specify up to 16 211.Dq pad 212bytes to fill out the packet you send. 213This is useful for diagnosing data-dependent problems in a network. 214For example, 215.Dq Li \-p ff 216will cause the sent packet to be filled with all 217ones. 218.\" new ipsec 219.It Fl P Ar policy 220.Ar policy 221specifies IPsec policy to be used for the probe. 222.It Fl q 223Quiet output. 224Nothing is displayed except the summary lines at startup time and 225when finished. 226.It Fl R 227Make the kernel believe that the target 228.Ar host 229(or the first 230.Ar hop 231if you specify 232.Ar hops ) 233is reachable, by injecting upper-layer reachability confirmation hint. 234The option is meaningful only if the target 235.Ar host 236(or the first hop) 237is a neighbor. 238.It Fl S Ar sourceaddr 239Specifies the source address of request packets. 240The source address must be one of the unicast addresses of the sending node. 241If the outgoing interface is specified by the 242.Fl I 243option as well, 244.Ar sourceaddr 245needs to be an address assigned to the specified interface. 246.It Fl s Ar packetsize 247Specifies the number of data bytes to be sent. 248The default is 56, which translates into 64 249.Tn ICMP 250data bytes when combined 251with the 8 bytes of 252.Tn ICMP 253header data. 254You may need to specify 255.Fl b 256as well to extend socket buffer size. 257.It Fl t 258Generate ICMPv6 Node Information supported query types query, 259rather than echo-request. 260.Fl s 261has no effect if 262.Fl t 263is specified. 264.It Fl v 265Verbose output. 266.Tn ICMP 267packets other than 268.Tn ECHO_RESPONSE 269that are received are listed. 270.It Fl w 271Generate ICMPv6 Node Information DNS Name query, rather than echo-request. 272.Fl s 273has no effect if 274.Fl w 275is specified. 276.It Fl W 277Same as 278.Fl w , 279but with old packet format based on 03 draft. 280This option is present for backward compatibility. 281.Fl s 282has no effect if 283.Fl w 284is specified. 285.It Ar hops 286IPv6 addresses for intermediate nodes, 287which will be put into type 0 routing header. 288.It Ar host 289IPv6 address of the final destination node. 290.El 291.Pp 292When using 293.Nm 294for fault isolation, it should first be run on the local host, to verify 295that the local network interface is up and running. 296Then, hosts and gateways further and further away should be 297.Dq pinged . 298Round-trip times and packet loss statistics are computed. 299If duplicate packets are received, they are not included in the packet 300loss calculation, although the round trip time of these packets is used 301in calculating the round-trip time statistics. 302When the specified number of packets have been sent 303(and received) 304or if the program is terminated with a 305.Dv SIGINT , 306a brief summary is displayed, showing the number of packets sent and 307received, and the minimum, mean, maximum, and standard deviation of 308the round-trip times. 309.Pp 310If 311.Nm 312receives a 313.Dv SIGINFO 314(see the 315.Cm status 316argument for 317.Xr stty 1 ) 318signal, the current number of packets sent and received, and the 319minimum, mean, maximum, and standard deviation of the round-trip times 320will be written to the standard output in the same format as the 321standard completion message. 322.Pp 323This program is intended for use in network testing, measurement and 324management. 325Because of the load it can impose on the network, it is unwise to use 326.Nm 327during normal operations or from automated scripts. 328.\" .Sh ICMP PACKET DETAILS 329.\" An IP header without options is 20 bytes. 330.\" An 331.\" .Tn ICMP 332.\" .Tn ECHO_REQUEST 333.\" packet contains an additional 8 bytes worth of 334.\" .Tn ICMP 335.\" header followed by an arbitrary amount of data. 336.\" When a 337.\" .Ar packetsize 338.\" is given, this indicated the size of this extra piece of data 339.\" (the default is 56). 340.\" Thus the amount of data received inside of an IP packet of type 341.\" .Tn ICMP 342.\" .Tn ECHO_REPLY 343.\" will always be 8 bytes more than the requested data space 344.\" (the 345.\" .Tn ICMP 346.\" header). 347.\" .Pp 348.\" If the data space is at least eight bytes large, 349.\" .Nm 350.\" uses the first eight bytes of this space to include a timestamp which 351.\" it uses in the computation of round trip times. 352.\" If less than eight bytes of pad are specified, no round trip times are 353.\" given. 354.Sh DUPLICATE AND DAMAGED PACKETS 355The 356.Nm 357utility will report duplicate and damaged packets. 358Duplicate packets should never occur when pinging a unicast address, 359and seem to be caused by 360inappropriate link-level retransmissions. 361Duplicates may occur in many situations and are rarely 362(if ever) 363a good sign, although the presence of low levels of duplicates may not 364always be cause for alarm. 365Duplicates are expected when pinging a broadcast or multicast address, 366since they are not really duplicates but replies from different hosts 367to the same request. 368.Pp 369Damaged packets are obviously serious cause for alarm and often 370indicate broken hardware somewhere in the 371.Nm 372packet's path 373(in the network or in the hosts). 374.Sh TRYING DIFFERENT DATA PATTERNS 375The 376(inter)network 377layer should never treat packets differently depending on the data 378contained in the data portion. 379Unfortunately, data-dependent problems have been known to sneak into 380networks and remain undetected for long periods of time. 381In many cases the particular pattern that will have problems is something 382that does not have sufficient 383.Dq transitions , 384such as all ones or all zeros, or a pattern right at the edge, such as 385almost all zeros. 386It is not 387necessarily enough to specify a data pattern of all zeros (for example) 388on the command line because the pattern that is of interest is 389at the data link level, and the relationship between what you type and 390what the controllers transmit can be complicated. 391.Pp 392This means that if you have a data-dependent problem you will probably 393have to do a lot of testing to find it. 394If you are lucky, you may manage to find a file that either 395cannot 396be sent across your network or that takes much longer to transfer than 397other similar length files. 398You can then examine this file for repeated patterns that you can test 399using the 400.Fl p 401option of 402.Nm . 403.Sh EXAMPLES 404Normally, 405.Nm 406works just like 407.Xr ping 8 408would work; the following will send ICMPv6 echo request to 409.Li dst.foo.com . 410.Bd -literal -offset indent 411ping6 -n dst.foo.com 412.Ed 413.Pp 414The following will probe hostnames for all nodes on the network link attached to 415.Li wi0 416interface. 417The address 418.Li ff02::1 419is named the link-local all-node multicast address, and the packet would 420reach every node on the network link. 421.Bd -literal -offset indent 422ping6 -w ff02::1%wi0 423.Ed 424.Pp 425The following will probe addresses assigned to the destination node, 426.Li dst.foo.com . 427.Bd -literal -offset indent 428ping6 -a agl dst.foo.com 429.Ed 430.Sh DIAGNOSTICS 431The 432.Nm 433utility returns 0 on success (the host is alive), 434and non-zero if the arguments are incorrect or the host is not responding. 435.Sh SEE ALSO 436.Xr netstat 1 , 437.Xr icmp6 4 , 438.Xr inet6 4 , 439.Xr ip6 4 , 440.Xr ifconfig 8 , 441.Xr ping 8 , 442.Xr routed 8 , 443.Xr traceroute 8 , 444.Xr traceroute6 8 445.Rs 446.%A A. Conta 447.%A S. Deering 448.%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification" 449.%N RFC 2463 450.%D December 1998 451.Re 452.Rs 453.%A Matt Crawford 454.%T "IPv6 Node Information Queries" 455.%N draft-ietf-ipngwg-icmp-name-lookups-07.txt 456.%D August 2000 457.%O work in progress material 458.Re 459.Sh HISTORY 460The 461.Xr ping 8 462command appeared in 463.Bx 4.3 . 464The 465.Nm 466utility with IPv6 support first appeared in WIDE Hydrangea IPv6 protocol stack 467kit. 468.Pp 469IPv6 and IPsec support based on the KAME Project 470.Pa ( http://www.kame.net/ ) 471stack was initially integrated into 472.Fx 4.0 473.Sh BUGS 474There have been many discussions on why we separate 475.Nm 476and 477.Xr ping 8 . 478Some people argued that it would be more convenient to uniform the 479ping command for both IPv4 and IPv6. 480The followings are an answer to the request. 481.Pp 482From a developer's point of view: 483since the underling raw sockets API is totally different between IPv4 484and IPv6, we would end up having two types of code base. 485There would actually be less benefit to uniform the two commands 486into a single command from the developer's standpoint. 487.Pp 488From an operator's point of view: unlike ordinary network applications 489like remote login tools, we are usually aware of address family when using 490network management tools. 491We do not just want to know the reachability to the host, but want to know the 492reachability to the host via a particular network protocol such as 493IPv6. 494Thus, even if we had a unified 495.Xr ping 8 496command for both IPv4 and IPv6, we would usually type a 497.Fl 6 498or 499.Fl 4 500option (or something like those) to specify the particular address family. 501This essentially means that we have two different commands. 502