1.\" $NetBSD: ping6.8,v 1.27 2006/05/18 00:50:08 rpaulo 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 May 18, 2006 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 dfHmnNqRtvwW 43.\" old IPsec 44.\" .Op Fl AdEfnNqRtvwW 45.Bk -words 46.Op Fl a Ar addrtype 47.Ek 48.Bk -words 49.Op Fl b Ar bufsiz 50.Ek 51.Bk -words 52.Op Fl c Ar count 53.Ek 54.Bk -words 55.Op Fl g Ar gateway 56.Ek 57.Bk -words 58.Op Fl h Ar hoplimit 59.Ek 60.Bk -words 61.Op Fl I Ar interface 62.Ek 63.Bk -words 64.Op Fl i Ar wait 65.Ek 66.Bk -words 67.Op Fl l Ar preload 68.Ek 69.Bk -words 70.Op Fl p Ar pattern 71.Ek 72.Bk -words 73.\" new IPsec 74.Op Fl P Ar policy 75.Ek 76.Bk -words 77.Op Fl S Ar sourceaddr 78.Ek 79.Bk -words 80.Op Fl s Ar packetsize 81.Ek 82.Bk -words 83.Op Ar hops ... 84.Ek 85.Bk -words 86.Ar host 87.Ek 88.Sh DESCRIPTION 89.Nm 90uses 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.\" .Pq 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 unicast addresses from all of the responder's interfaces. 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.Pq 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.\" .Pq 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 g Ar gateway 166Specifies to use 167.Ar gateway 168as the next hop to the destination. 169The gateway must be a neighbor of the sending node. 170.It Fl H 171Specifies to try reverse-lookup of IPv6 addresses. 172The 173.Nm 174command does not try reverse-lookup unless the option is specified. 175.It Fl h Ar hoplimit 176Set the IPv6 hoplimit. 177.It Fl I Ar interface 178Source packets with the given interface address. 179This flag applies if the ping destination is a multicast address, 180or link-local/site-local unicast address. 181.It Fl i Ar wait 182Wait 183.Ar wait 184seconds 185.Em between sending each packet . 186The default is to wait for one second between each packet. 187This option is incompatible with the 188.Fl f 189option. 190.It Fl l Ar preload 191If 192.Ar preload 193is specified, 194.Nm 195sends that many packets as fast as possible before falling into its normal 196mode of behavior. 197Only the super-user may use this option. 198.It Fl m 199By default, 200.Nm 201asks the kernel to fragment packets to fit into the minimum IPv6 MTU. 202.Fl m 203will suppress the behavior in the following two levels: 204when the option is specified once, the behavior will be disabled for 205unicast packets. 206When the option is specified more than once, it will be disabled for both 207unicast and multicast packets. 208.It Fl n 209Numeric output only. 210No attempt will be made to lookup symbolic names from addresses in the reply. 211.It Fl N 212Probe node information multicast group 213.Pq Li ff02::2:xxxx:xxxx . 214.Ar host 215must be string hostname of the target 216.Pq must not be a numeric IPv6 address . 217Node information multicast group will be computed based on given 218.Ar host , 219and will be used as the final destination. 220Since node information multicast group is a link-local multicast group, 221outgoing interface needs to be specified by 222.Fl I 223option. 224.It Fl p Ar pattern 225You may specify up to 16 226.Dq pad 227bytes to fill out the packet you send. 228This is useful for diagnosing data-dependent problems in a network. 229For example, 230.Dq Li \-p ff 231will cause the sent packet to be filled with all 232ones. 233.\" new IPsec 234.It Fl P Ar policy 235.Ar policy 236specifies IPsec policy to be used for the probe. 237.It Fl q 238Quiet output. 239Nothing is displayed except the summary lines at startup time and 240when finished. 241.It Fl R 242Make the kernel believe that the target 243.Ar host 244.Po 245or the first 246.Ar hop 247if you specify 248.Ar hops 249.Pc 250is reachable, by injecting upper-layer reachability confirmation hint. 251The option is meaningful only if the target 252.Ar host 253.Pq or the first hop 254is a neighbor. 255.It Fl S Ar sourceaddr 256Specifies the source address of request packets. 257The source address must be one of the unicast addresses of the sending node, 258and must be numeric. 259.It Fl s Ar packetsize 260Specifies the number of data bytes to be sent. 261The default is 56, which translates into 64 262.Tn ICMP 263data bytes when combined 264with the 8 bytes of 265.Tn ICMP 266header data. 267You may need to specify 268.Fl b 269as well to extend socket buffer size. 270.It Fl t 271Generate ICMPv6 Node Information supported query types query, 272rather than echo-request. 273.Fl s 274has no effect if 275.Fl t 276is specified. 277.It Fl v 278Verbose output. 279.Tn ICMP 280packets other than 281.Tn ECHO_RESPONSE 282that are received are listed. 283.It Fl w 284Generate ICMPv6 Node Information DNS Name query, rather than echo-request. 285.Fl s 286has no effect if 287.Fl w 288is specified. 289.It Fl W 290Same as 291.Fl w , 292but with old packet format based on 03 draft. 293This option is present for backward compatibility. 294.Fl s 295has no effect if 296.Fl w 297is specified. 298.It Ar hops 299IPv6 addresses for intermediate nodes, 300which will be put into type 0 routing header. 301.It Ar host 302IPv6 address of the final destination node. 303.El 304.Pp 305When using 306.Nm 307for fault isolation, it should first be run on the local host, to verify 308that the local network interface is up and running. 309Then, hosts and gateways further and further away should be 310.Dq pinged . 311Round-trip times and packet loss statistics are computed. 312If duplicate packets are received, they are not included in the packet 313loss calculation, although the round trip time of these packets is used 314in calculating the round-trip time statistics. 315When the specified number of packets have been sent 316.Pq and received 317or if the program is terminated with a 318.Dv SIGINT , 319a brief summary is displayed, showing the number of packets sent and 320received, and the minimum, maximum, mean, and standard deviation of 321the round-trip times. 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.\" .Pq 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.\" .Pq the Tn ICMP header . 345.\" .Pp 346.\" If the data space is at least eight bytes large, 347.\" .Nm 348.\" uses the first eight bytes of this space to include a timestamp which 349.\" it uses in the computation of round trip times. 350.\" If less than eight bytes of pad are specified, no round trip times are 351.\" given. 352.Sh DUPLICATE AND DAMAGED PACKETS 353.Nm 354will report duplicate and damaged packets. 355Duplicate packets should never occur when pinging a unicast address, 356and seem to be caused by 357inappropriate link-level retransmissions. 358Duplicates may occur in many situations and are rarely 359.Pq if ever 360a good sign, although the presence of low levels of duplicates may not 361always be cause for alarm. 362Duplicates are expected when pinging a multicast address, 363since they are not really duplicates but replies from different hosts 364to the same request. 365.Pp 366Damaged packets are obviously serious cause for alarm and often 367indicate broken hardware somewhere in the 368.Nm 369packet's path 370.Pq in the network or in the hosts . 371.Sh TRYING DIFFERENT DATA PATTERNS 372The 373(inter)network 374layer should never treat packets differently depending on the data 375contained in the data portion. 376Unfortunately, data-dependent problems have been known to sneak into 377networks and remain undetected for long periods of time. 378In many cases the particular pattern that will have problems is something 379that does not have sufficient 380.Dq transitions , 381such as all ones or all zeros, or a pattern right at the edge, such as 382almost all zeros. 383It is not 384necessarily enough to specify a data pattern of all zeros (for example) 385on the command line because the pattern that is of interest is 386at the data link level, and the relationship between what you type and 387what the controllers transmit can be complicated. 388.Pp 389This means that if you have a data-dependent problem you will probably 390have to do a lot of testing to find it. 391If you are lucky, you may manage to find a file that either 392cannot 393be sent across your network or that takes much longer to transfer than 394other similar length files. 395You can then examine this file for repeated patterns that you can test 396using the 397.Fl p 398option of 399.Nm Ns . 400.Sh EXIT STATUS 401.Nm 402exits with 0 on success (the host is alive), 403and non-zero if the arguments are incorrect or the host is not responding. 404.Sh EXAMPLES 405Normally, 406.Nm 407works just like 408.Xr ping 8 409would work; the following will send ICMPv6 echo request to 410.Li dst.foo.com . 411.Bd -literal -offset indent 412ping6 -n dst.foo.com 413.Ed 414.Pp 415The following will probe hostnames for all nodes on the network link attached to 416.Li wi0 417interface. 418The address 419.Li ff02::1 420is named the link-local all-node multicast address, and the packet would 421reach every node on the network link. 422.Bd -literal -offset indent 423ping6 -w ff02::1%wi0 424.Ed 425.Pp 426The following will probe addresses assigned to the destination node, 427.Li dst.foo.com . 428.Bd -literal -offset indent 429ping6 -a agl dst.foo.com 430.Ed 431.Sh SEE ALSO 432.Xr netstat 1 , 433.Xr icmp6 4 , 434.Xr inet6 4 , 435.Xr ip6 4 , 436.Xr ifconfig 8 , 437.Xr ping 8 , 438.Xr routed 8 , 439.Xr traceroute 8 , 440.Xr traceroute6 8 441.Rs 442.%A A. Conta 443.%A S. Deering 444.%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification" 445.%N RFC 2463 446.%D December 1998 447.Re 448.Rs 449.%A Matt Crawford 450.%T "IPv6 Node Information Queries" 451.%N draft-ietf-ipngwg-icmp-name-lookups-09.txt 452.%D May 2002 453.%O work in progress material 454.Re 455.Sh HISTORY 456The 457.Xr ping 8 458command appeared in 459.Bx 4.3 . 460The 461.Nm 462command with IPv6 support first appeared in the WIDE Hydrangea IPv6 463protocol stack kit. 464.Sh BUGS 465.\" except for bsdi 466.Nm 467is intentionally separate from 468.Xr ping 8 . 469