1.\" $NetBSD: ping6.8,v 1.30 2015/05/15 08:02:39 kefren Exp $ 2.\" $KAME: ping6.8,v 1.57 2002/05/26 13:18:25 itojun Exp $ 3.\" 4.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the project nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.Dd April 23, 2015 32.Dt PING6 8 33.Os 34.Sh NAME 35.Nm ping6 36.Nd send 37.Tn ICMPv6 ECHO_REQUEST 38packets to network hosts 39.Sh SYNOPSIS 40.Nm ping6 41.\" without IPsec, or new IPsec 42.Op Fl dfHmnNoqRtvwW 43.\" old IPsec 44.\" .Op Fl AdEfnNqRtvwW 45.Op Fl a Ar addrtype 46.Op Fl b Ar bufsiz 47.Op Fl c Ar count 48.Op Fl g Ar gateway 49.Op Fl h Ar hoplimit 50.Op Fl I Ar interface 51.Op Fl i Ar wait 52.Op Fl l Ar preload 53.Op Fl p Ar pattern 54.\" new IPsec 55.Op Fl P Ar policy 56.Op Fl S Ar sourceaddr 57.Op Fl s Ar packetsize 58.Op Fl x Ar maxwait 59.Op Fl X Ar deadline 60.Op Ar hops ... 61.Ar host 62.Sh DESCRIPTION 63.Nm 64uses the 65.Tn ICMPv6 66protocol's mandatory 67.Tn ICMP6_ECHO_REQUEST 68datagram to elicit an 69.Tn ICMP6_ECHO_REPLY 70from a host or gateway. 71.Tn ICMP6_ECHO_REQUEST 72datagrams (``pings'') have an IPv6 header, 73and 74.Tn ICMPv6 75header formatted as documented in RFC 2463. 76The options are as follows: 77.Bl -tag -width Ds 78.\" old IPsec 79.\" .It Fl A 80.\" Enables transport-mode IPsec authentication header 81.\" .Pq experimental . 82.It Fl a Ar addrtype 83Generate ICMPv6 Node Information Node Addresses query, rather than echo-request. 84.Ar addrtype 85must be a string constructed of the following characters. 86.Bl -tag -width Ds -compact 87.It Ic a 88requests unicast addresses from all of the responder's interfaces. 89If the character is omitted, 90only those addresses which belong to the interface which has the 91responder's address are requests. 92.It Ic c 93requests responder's IPv4-compatible and IPv4-mapped addresses. 94.It Ic g 95requests responder's global-scope addresses. 96.It Ic s 97requests responder's site-local addresses. 98.It Ic l 99requests responder's link-local addresses. 100.It Ic A 101requests responder's anycast addresses. 102Without this character, the responder will return unicast addresses only. 103With this character, the responder will return anycast addresses only. 104Note that the specification does not specify how to get responder's 105anycast addresses. 106This is an experimental option. 107.El 108.It Fl b Ar bufsiz 109Set socket buffer size. 110.It Fl c Ar count 111Stop after sending 112.Pq and receiving 113.Ar count 114.Tn ECHO_RESPONSE 115packets. 116.It Fl d 117Set the 118.Dv SO_DEBUG 119option on the socket being used. 120.\" .It Fl E 121.\" Enables transport-mode IPsec encapsulated security payload 122.\" .Pq experimental . 123.It Fl f 124Flood ping. 125Outputs packets as fast as they come back or one hundred times per second, 126whichever is more. 127For every 128.Tn ECHO_REQUEST 129sent a period 130.Dq \&. 131is printed, while for every 132.Tn ECHO_REPLY 133received a backspace is printed. 134This provides a rapid display of how many packets are being dropped. 135Only the super-user may use this option. 136.Bf -emphasis 137This can be very hard on a network and should be used with caution. 138.Ef 139.It Fl g Ar gateway 140Specifies to use 141.Ar gateway 142as the next hop to the destination. 143The gateway must be a neighbor of the sending node. 144.It Fl H 145Specifies to try reverse-lookup of IPv6 addresses. 146The 147.Nm 148command does not try reverse-lookup unless the option is specified. 149.It Fl h Ar hoplimit 150Set the IPv6 hoplimit. 151.It Fl I Ar interface 152Source packets with the given interface address. 153This flag applies if the ping destination is a multicast address, 154or link-local/site-local unicast address. 155.It Fl i Ar wait 156Wait 157.Ar wait 158seconds 159.Em between sending each packet . 160The default is to wait for one second between each packet. 161This option is incompatible with the 162.Fl f 163option. 164.It Fl l Ar preload 165If 166.Ar preload 167is specified, 168.Nm 169sends that many packets as fast as possible before falling into its normal 170mode of behavior. 171Only the super-user may use this option. 172.It Fl m 173By default, 174.Nm 175asks the kernel to fragment packets to fit into the minimum IPv6 MTU. 176.Fl m 177will suppress the behavior in the following two levels: 178when the option is specified once, the behavior will be disabled for 179unicast packets. 180When the option is specified more than once, it will be disabled for both 181unicast and multicast packets. 182.It Fl n 183Numeric output only. 184No attempt will be made to lookup symbolic names from addresses in the reply. 185.It Fl N 186Probe node information multicast group 187.Pq Li ff02::2:xxxx:xxxx . 188.Ar host 189must be string hostname of the target 190.Pq must not be a numeric IPv6 address . 191Node information multicast group will be computed based on given 192.Ar host , 193and will be used as the final destination. 194Since node information multicast group is a link-local multicast group, 195outgoing interface needs to be specified by 196.Fl I 197option. 198.It Fl o 199Exit successfully after receiving one reply packet. 200.It Fl p Ar pattern 201You may specify up to 16 202.Dq pad 203bytes to fill out the packet you send. 204This is useful for diagnosing data-dependent problems in a network. 205For example, 206.Dq Li \-p ff 207will cause the sent packet to be filled with all 208ones. 209.\" new IPsec 210.It Fl P Ar policy 211.Ar policy 212specifies IPsec policy to be used for the probe. 213.It Fl q 214Quiet output. 215Nothing is displayed except the summary lines at startup time and 216when finished. 217.It Fl R 218Make the kernel believe that the target 219.Ar host 220.Po 221or the first 222.Ar hop 223if you specify 224.Ar hops 225.Pc 226is reachable, by injecting upper-layer reachability confirmation hint. 227The option is meaningful only if the target 228.Ar host 229.Pq or the first hop 230is a neighbor. 231.It Fl S Ar sourceaddr 232Specifies the source address of request packets. 233The source address must be one of the unicast addresses of the sending node, 234and must be numeric. 235.It Fl s Ar packetsize 236Specifies the number of data bytes to be sent. 237The default is 56, which translates into 64 238.Tn ICMP 239data bytes when combined 240with the 8 bytes of 241.Tn ICMP 242header data. 243You may need to specify 244.Fl b 245as well to extend socket buffer size. 246.It Fl t 247Generate ICMPv6 Node Information supported query types query, 248rather than echo-request. 249.Fl s 250has no effect if 251.Fl t 252is specified. 253.It Fl v 254Verbose output. 255.Tn ICMP 256packets other than 257.Tn ECHO_RESPONSE 258that are received are listed. 259.It Fl w 260Generate ICMPv6 Node Information DNS Name query, rather than echo-request. 261.Fl s 262has no effect if 263.Fl w 264is specified. 265.It Fl W 266Same as 267.Fl w , 268but with old packet format based on 03 draft. 269This option is present for backward compatibility. 270.Fl s 271has no effect if 272.Fl w 273is specified. 274.It Fl x Ar maxwait 275Time in milliseconds to wait for a reply for each packet sent. 276.It Fl X Ar deadline 277Specify a timeout, in seconds, before ping exits regardless of 278how many packets have been received. 279.It Ar hops 280IPv6 addresses for intermediate nodes, 281which will be put into type 0 routing header. 282.It Ar host 283IPv6 address of the final destination node. 284.El 285.Pp 286When using 287.Nm 288for fault isolation, it should first be run on the local host, to verify 289that the local network interface is up and running. 290Then, hosts and gateways further and further away should be 291.Dq pinged . 292Round-trip times and packet loss statistics are computed. 293If duplicate packets are received, they are not included in the packet 294loss calculation, although the round trip time of these packets is used 295in calculating the round-trip time statistics. 296When the specified number of packets have been sent 297.Pq and received 298or if the program is terminated with a 299.Dv SIGINT , 300a brief summary is displayed, showing the number of packets sent and 301received, and the minimum, maximum, mean, and standard deviation of 302the round-trip times. 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.\" .Pq 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.\" .Pq the Tn ICMP header . 326.\" .Pp 327.\" If the data space is at least eight bytes large, 328.\" .Nm 329.\" uses the first eight bytes of this space to include a timestamp which 330.\" it uses in the computation of round trip times. 331.\" If less than eight bytes of pad are specified, no round trip times are 332.\" given. 333.Sh DUPLICATE AND DAMAGED PACKETS 334.Nm 335will report duplicate and damaged packets. 336Duplicate packets should never occur when pinging a unicast address, 337and seem to be caused by 338inappropriate link-level retransmissions. 339Duplicates may occur in many situations and are rarely 340.Pq if ever 341a good sign, although the presence of low levels of duplicates may not 342always be cause for alarm. 343Duplicates are expected when pinging a multicast address, 344since they are not really duplicates but replies from different hosts 345to the same request. 346.Pp 347Damaged packets are obviously serious cause for alarm and often 348indicate broken hardware somewhere in the 349.Nm 350packet's path 351.Pq in the network or in the hosts . 352.Sh TRYING DIFFERENT DATA PATTERNS 353The 354(inter)network 355layer should never treat packets differently depending on the data 356contained in the data portion. 357Unfortunately, data-dependent problems have been known to sneak into 358networks and remain undetected for long periods of time. 359In many cases the particular pattern that will have problems is something 360that does not have sufficient 361.Dq transitions , 362such as all ones or all zeros, or a pattern right at the edge, such as 363almost all zeros. 364It is not 365necessarily enough to specify a data pattern of all zeros (for example) 366on the command line because the pattern that is of interest is 367at the data link level, and the relationship between what you type and 368what the controllers transmit can be complicated. 369.Pp 370This means that if you have a data-dependent problem you will probably 371have to do a lot of testing to find it. 372If you are lucky, you may manage to find a file that either 373cannot 374be sent across your network or that takes much longer to transfer than 375other similar length files. 376You can then examine this file for repeated patterns that you can test 377using the 378.Fl p 379option of 380.Nm Ns . 381.Sh EXIT STATUS 382.Nm 383exits with 0 on success (the host is alive), 384and non-zero if the arguments are incorrect or the host is not responding. 385.Sh EXAMPLES 386Normally, 387.Nm 388works just like 389.Xr ping 8 390would work; the following will send ICMPv6 echo request to 391.Li dst.foo.com . 392.Bd -literal -offset indent 393ping6 -n dst.foo.com 394.Ed 395.Pp 396The following will probe hostnames for all nodes on the network link attached to 397.Li wi0 398interface. 399The address 400.Li ff02::1 401is named the link-local all-node multicast address, and the packet would 402reach every node on the network link. 403.Bd -literal -offset indent 404ping6 -w ff02::1%wi0 405.Ed 406.Pp 407The following will probe addresses assigned to the destination node, 408.Li dst.foo.com . 409.Bd -literal -offset indent 410ping6 -a agl dst.foo.com 411.Ed 412.Sh SEE ALSO 413.Xr netstat 1 , 414.Xr icmp6 4 , 415.Xr inet6 4 , 416.Xr ip6 4 , 417.Xr ifconfig 8 , 418.Xr ping 8 , 419.Xr routed 8 , 420.Xr traceroute 8 , 421.Xr traceroute6 8 422.Rs 423.%A A. Conta 424.%A S. Deering 425.%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification" 426.%N RFC 2463 427.%D December 1998 428.Re 429.Rs 430.%A Matt Crawford 431.%T "IPv6 Node Information Queries" 432.%N draft-ietf-ipngwg-icmp-name-lookups-09.txt 433.%D May 2002 434.%O work in progress material 435.Re 436.Sh HISTORY 437The 438.Xr ping 8 439command appeared in 440.Bx 4.3 . 441The 442.Nm 443command with IPv6 support first appeared in the WIDE Hydrangea IPv6 444protocol stack kit. 445.Sh BUGS 446.\" except for bsdi 447.Nm 448is intentionally separate from 449.Xr ping 8 . 450