| blob | 42ee8c13b1b883d070c3959f44c9a1ea250369ba |
1 .\" $KAME: ping6.8,v 1.43 2001/06/28 06:54:29 suz Exp $
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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
40 packets 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
88 The
89 .Nm
90 utility uses the
91 .Tn ICMPv6
92 protocol's mandatory
93 .Tn ICMP6_ECHO_REQUEST
94 datagram to elicit an
95 .Tn ICMP6_ECHO_REPLY
96 from a host or gateway.
97 .Tn ICMP6_ECHO_REQUEST
98 datagrams (``pings'') have an IPv6 header,
99 and
100 .Tn ICMPv6
101 header formatted as documented in RFC 2463.
102 The 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
109 Generate ICMPv6 Node Information Node Addresses query, rather than echo-request.
110 .Ar addrtype
111 must be a string constructed of the following characters.
112 .Bl -tag -width Ds -compact
113 .It Ic a
114 requests all the responder's unicast addresses.
115 If the character is omitted,
116 only those addresses which belong to the interface which has the
117 responder's address are requests.
118 .It Ic c
119 requests responder's IPv4-compatible and IPv4-mapped addresses.
120 .It Ic g
121 requests responder's global-scope addresses.
122 .It Ic s
123 requests responder's site-local addresses.
124 .It Ic l
125 requests responder's link-local addresses.
126 .It Ic A
127 requests responder's anycast addresses.
128 Without this character, the responder will return unicast addresses only.
129 With this character, the responder will return anycast addresses only.
130 Note that the specification does not specify how to get responder's
131 anycast addresses.
132 This is an experimental option.
133 .El
134 .It Fl b Ar bufsiz
135 Set socket buffer size.
136 .It Fl c Ar count
137 Stop after sending
138 (and receiving)
139 .Ar count
140 .Tn ECHO_RESPONSE
141 packets.
142 .It Fl d
143 Set the
144 .Dv SO_DEBUG
145 option on the socket being used.
146 .\" .It Fl E
147 .\" Enables transport-mode IPsec encapsulated security payload
148 .\" (experimental).
149 .It Fl f
150 Flood ping.
151 Outputs packets as fast as they come back or one hundred times per second,
152 whichever is more.
153 For every
154 .Tn ECHO_REQUEST
155 sent a period
156 .Dq .\&
157 is printed, while for every
158 .Tn ECHO_REPLY
159 received a backspace is printed.
160 This provides a rapid display of how many packets are being dropped.
161 Only the super-user may use this option.
162 .Bf -emphasis
163 This can be very hard on a network and should be used with caution.
164 .Ef
165 .It Fl H
166 Specifies to try reverse-lookup of IPv6 addresses.
167 The
168 .Nm
169 utility does not try reverse-lookup unless the option is specified.
170 .It Fl h Ar hoplimit
171 Set the IPv6 hoplimit.
172 .It Fl I Ar interface
173 Source packets with the given interface address.
174 This flag applies if the ping destination is a multicast address,
175 or link-local/site-local unicast address.
176 .It Fl i Ar wait
177 Wait
178 .Ar wait
179 seconds
180 .Em between sending each packet .
181 The default is to wait for one second between each packet.
182 This option is incompatible with the
183 .Fl f
184 option.
185 .It Fl l Ar preload
186 If
187 .Ar preload
188 is specified,
189 .Nm
190 sends that many packets as fast as possible before falling into its normal
191 mode of behavior.
192 Only the super-user may use this option.
193 .It Fl n
194 Numeric output only.
195 No attempt will be made to lookup symbolic names from addresses in the reply.
196 .It Fl N
197 Probe node information multicast group
198 .Pq Li ff02::2:xxxx:xxxx .
199 .Ar host
200 must be string hostname of the target
201 (must not be a numeric IPv6 address).
202 Node information multicast group will be computed based on given
203 .Ar host ,
204 and will be used as the final destination.
205 Since node information multicast group is a link-local multicast group,
206 destination link needs to be specified by
207 .Fl I
208 option.
209 .It Fl p Ar pattern
210 You may specify up to 16
211 .Dq pad
212 bytes to fill out the packet you send.
213 This is useful for diagnosing data-dependent problems in a network.
214 For example,
215 .Dq Li \-p ff
216 will cause the sent packet to be filled with all
217 ones.
218 .\" new ipsec
219 .It Fl P Ar policy
220 .Ar policy
221 specifies IPsec policy to be used for the probe.
222 .It Fl q
223 Quiet output.
224 Nothing is displayed except the summary lines at startup time and
225 when finished.
226 .It Fl R
227 Make the kernel believe that the target
228 .Ar host
229 (or the first
230 .Ar hop
231 if you specify
232 .Ar hops )
233 is reachable, by injecting upper-layer reachability confirmation hint.
234 The option is meaningful only if the target
235 .Ar host
236 (or the first hop)
237 is a neighbor.
238 .It Fl S Ar sourceaddr
239 Specifies the source address of request packets.
240 The source address must be one of the unicast addresses of the sending node.
241 If the outgoing interface is specified by the
242 .Fl I
243 option as well,
244 .Ar sourceaddr
245 needs to be an address assigned to the specified interface.
246 .It Fl s Ar packetsize
247 Specifies the number of data bytes to be sent.
248 The default is 56, which translates into 64
249 .Tn ICMP
250 data bytes when combined
251 with the 8 bytes of
252 .Tn ICMP
253 header data.
254 You may need to specify
255 .Fl b
256 as well to extend socket buffer size.
257 .It Fl t
258 Generate ICMPv6 Node Information supported query types query,
259 rather than echo-request.
260 .Fl s
261 has no effect if
262 .Fl t
263 is specified.
264 .It Fl v
265 Verbose output.
266 .Tn ICMP
267 packets other than
268 .Tn ECHO_RESPONSE
269 that are received are listed.
270 .It Fl w
271 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
272 .Fl s
273 has no effect if
274 .Fl w
275 is specified.
276 .It Fl W
277 Same as
278 .Fl w ,
279 but with old packet format based on 03 draft.
280 This option is present for backward compatibility.
281 .Fl s
282 has no effect if
283 .Fl w
284 is specified.
285 .It Ar hops
286 IPv6 addresses for intermediate nodes,
287 which will be put into type 0 routing header.
288 .It Ar host
289 IPv6 address of the final destination node.
290 .El
291 .Pp
292 When using
293 .Nm
294 for fault isolation, it should first be run on the local host, to verify
295 that the local network interface is up and running.
296 Then, hosts and gateways further and further away should be
297 .Dq pinged .
298 Round-trip times and packet loss statistics are computed.
299 If duplicate packets are received, they are not included in the packet
300 loss calculation, although the round trip time of these packets is used
301 in calculating the round-trip time statistics.
302 When the specified number of packets have been sent
303 (and received)
304 or if the program is terminated with a
305 .Dv SIGINT ,
306 a brief summary is displayed, showing the number of packets sent and
307 received, and the minimum, mean, maximum, and standard deviation of
308 the round-trip times.
309 .Pp
310 If
311 .Nm
312 receives a
313 .Dv SIGINFO
314 (see the
315 .Cm status
316 argument for
317 .Xr stty 1 )
318 signal, the current number of packets sent and received, and the
319 minimum, mean, maximum, and standard deviation of the round-trip times
320 will be written to the standard output in the same format as the
321 standard completion message.
322 .Pp
323 This program is intended for use in network testing, measurement and
324 management.
325 Because of the load it can impose on the network, it is unwise to use
326 .Nm
327 during 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
355 The
356 .Nm
357 utility will report duplicate and damaged packets.
358 Duplicate packets should never occur when pinging a unicast address,
359 and seem to be caused by
360 inappropriate link-level retransmissions.
361 Duplicates may occur in many situations and are rarely
362 (if ever)
363 a good sign, although the presence of low levels of duplicates may not
364 always be cause for alarm.
365 Duplicates are expected when pinging a broadcast or multicast address,
366 since they are not really duplicates but replies from different hosts
367 to the same request.
368 .Pp
369 Damaged packets are obviously serious cause for alarm and often
370 indicate broken hardware somewhere in the
371 .Nm
372 packet's path
373 (in the network or in the hosts).
374 .Sh TRYING DIFFERENT DATA PATTERNS
375 The
376 (inter)network
377 layer should never treat packets differently depending on the data
378 contained in the data portion.
379 Unfortunately, data-dependent problems have been known to sneak into
380 networks and remain undetected for long periods of time.
381 In many cases the particular pattern that will have problems is something
382 that does not have sufficient
383 .Dq transitions ,
384 such as all ones or all zeros, or a pattern right at the edge, such as
385 almost all zeros.
386 It is not
387 necessarily enough to specify a data pattern of all zeros (for example)
388 on the command line because the pattern that is of interest is
389 at the data link level, and the relationship between what you type and
390 what the controllers transmit can be complicated.
391 .Pp
392 This means that if you have a data-dependent problem you will probably
393 have to do a lot of testing to find it.
394 If you are lucky, you may manage to find a file that either
395 cannot
396 be sent across your network or that takes much longer to transfer than
397 other similar length files.
398 You can then examine this file for repeated patterns that you can test
399 using the
400 .Fl p
401 option of
402 .Nm .
403 .Sh EXAMPLES
404 Normally,
405 .Nm
406 works just like
407 .Xr ping 8
408 would work; the following will send ICMPv6 echo request to
409 .Li dst.foo.com .
410 .Bd -literal -offset indent
411 ping6 -n dst.foo.com
412 .Ed
413 .Pp
414 The following will probe hostnames for all nodes on the network link attached to
415 .Li wi0
416 interface.
417 The address
418 .Li ff02::1
419 is named the link-local all-node multicast address, and the packet would
420 reach every node on the network link.
421 .Bd -literal -offset indent
422 ping6 -w ff02::1%wi0
423 .Ed
424 .Pp
425 The following will probe addresses assigned to the destination node,
426 .Li dst.foo.com .
427 .Bd -literal -offset indent
428 ping6 -a agl dst.foo.com
429 .Ed
430 .Sh DIAGNOSTICS
431 The
432 .Nm
433 utility returns 0 on success (the host is alive),
434 and 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
460 The
461 .Xr ping 8
462 command appeared in
463 .Bx 4.3 .
464 The
465 .Nm
466 utility with IPv6 support first appeared in WIDE Hydrangea IPv6 protocol stack
467 kit.
468 .Pp
469 IPv6 and IPsec support based on the KAME Project
470 .Pa ( http://www.kame.net/ )
471 stack was initially integrated into
472 .Fx 4.0
473 .Sh BUGS
474 There have been many discussions on why we separate
475 .Nm
476 and
477 .Xr ping 8 .
478 Some people argued that it would be more convenient to uniform the
479 ping command for both IPv4 and IPv6.
480 The followings are an answer to the request.
481 .Pp
482 From a developer's point of view:
483 since the underling raw sockets API is totally different between IPv4
484 and IPv6, we would end up having two types of code base.
485 There would actually be less benefit to uniform the two commands
486 into a single command from the developer's standpoint.
487 .Pp
488 From an operator's point of view: unlike ordinary network applications
489 like remote login tools, we are usually aware of address family when using
490 network management tools.
491 We do not just want to know the reachability to the host, but want to know the
492 reachability to the host via a particular network protocol such as
493 IPv6.
494 Thus, even if we had a unified
495 .Xr ping 8
496 command for both IPv4 and IPv6, we would usually type a
497 .Fl 6
498 or
499 .Fl 4
500 option (or something like those) to specify the particular address family.
501 This essentially means that we have two different commands.