| blob | 21fb43bbba2c9ee40cf5225dd946c7ceef575f2b |
1 .\" $NetBSD: ping6.8,v 1.26 2006/05/05 00:03:22 rpaulo Exp $
2 .\" $KAME: ping6.8,v 1.57 2002/05/26 13:18:25 itojun Exp $
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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
38 packets 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
90 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 .\" .Pq 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 unicast addresses from all of the responder's interfaces.
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 .Pq 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 .\" .Pq 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 g Ar gateway
166 Specifies to use
167 .Ar gateway
168 as the next hop to the destination.
169 The gateway must be a neighbor of the sending node.
170 .It Fl H
171 Specifies to try reverse-lookup of IPv6 addresses.
172 The
173 .Nm
174 command does not try reverse-lookup unless the option is specified.
175 .It Fl h Ar hoplimit
176 Set the IPv6 hoplimit.
177 .It Fl I Ar interface
178 Source packets with the given interface address.
179 This flag applies if the ping destination is a multicast address,
180 or link-local/site-local unicast address.
181 .It Fl i Ar wait
182 Wait
183 .Ar wait
184 seconds
185 .Em between sending each packet .
186 The default is to wait for one second between each packet.
187 This option is incompatible with the
188 .Fl f
189 option.
190 .It Fl l Ar preload
191 If
192 .Ar preload
193 is specified,
194 .Nm
195 sends that many packets as fast as possible before falling into its normal
196 mode of behavior.
197 Only the super-user may use this option.
198 .It Fl m
199 By default,
200 .Nm
201 asks the kernel to fragment packets to fit into the minimum IPv6 MTU.
202 .Fl m
203 will suppress the behavior in the following two levels:
204 when the option is specified once, the behavior will be disabled for
205 unicast packets.
206 When the option is specified more than once, it will be disabled for both
207 unicast and multicast packets.
208 .It Fl n
209 Numeric output only.
210 No attempt will be made to lookup symbolic names from addresses in the reply.
211 .It Fl N
212 Probe node information multicast group
213 .Pq Li ff02::2:xxxx:xxxx .
214 .Ar host
215 must be string hostname of the target
216 .Pq must not be a numeric IPv6 address .
217 Node information multicast group will be computed based on given
218 .Ar host ,
219 and will be used as the final destination.
220 Since node information multicast group is a link-local multicast group,
221 outgoing interface needs to be specified by
222 .Fl I
223 option.
224 .It Fl p Ar pattern
225 You may specify up to 16
226 .Dq pad
227 bytes to fill out the packet you send.
228 This is useful for diagnosing data-dependent problems in a network.
229 For example,
230 .Dq Li \-p ff
231 will cause the sent packet to be filled with all
232 ones.
233 .\" new IPsec
234 .It Fl P Ar policy
235 .Ar policy
236 specifies IPsec policy to be used for the probe.
237 .It Fl q
238 Quiet output.
239 Nothing is displayed except the summary lines at startup time and
240 when finished.
241 .It Fl R
242 Make the kernel believe that the target
243 .Ar host
244 .Po
245 or the first
246 .Ar hop
247 if you specify
248 .Ar hops
249 .Pc
250 is reachable, by injecting upper-layer reachability confirmation hint.
251 The option is meaningful only if the target
252 .Ar host
253 .Pq or the first hop
254 is a neighbor.
255 .It Fl S Ar sourceaddr
256 Specifies the source address of request packets.
257 The source address must be one of the unicast addresses of the sending node,
258 and must be numeric.
259 .It Fl s Ar packetsize
260 Specifies the number of data bytes to be sent.
261 The default is 56, which translates into 64
262 .Tn ICMP
263 data bytes when combined
264 with the 8 bytes of
265 .Tn ICMP
266 header data.
267 You may need to specify
268 .Fl b
269 as well to extend socket buffer size.
270 .It Fl t
271 Generate ICMPv6 Node Information supported query types query,
272 rather than echo-request.
273 .Fl s
274 has no effect if
275 .Fl t
276 is specified.
277 .It Fl v
278 Verbose output.
279 .Tn ICMP
280 packets other than
281 .Tn ECHO_RESPONSE
282 that are received are listed.
283 .It Fl w
284 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
285 .Fl s
286 has no effect if
287 .Fl w
288 is specified.
289 .It Fl W
290 Same as
291 .Fl w ,
292 but with old packet format based on 03 draft.
293 This option is present for backward compatibility.
294 .Fl s
295 has no effect if
296 .Fl w
297 is specified.
298 .It Ar hops
299 IPv6 addresses for intermediate nodes,
300 which will be put into type 0 routing header.
301 .It Ar host
302 IPv6 address of the final destination node.
303 .El
304 .Pp
305 When using
306 .Nm
307 for fault isolation, it should first be run on the local host, to verify
308 that the local network interface is up and running.
309 Then, hosts and gateways further and further away should be
310 .Dq pinged .
311 Round-trip times and packet loss statistics are computed.
312 If duplicate packets are received, they are not included in the packet
313 loss calculation, although the round trip time of these packets is used
314 in calculating the round-trip time statistics.
315 When the specified number of packets have been sent
316 .Pq and received
317 or if the program is terminated with a
318 .Dv SIGINT ,
319 a brief summary is displayed, showing the number of packets sent and
320 received, and the minimum, maximum, mean, and standard deviation of
321 the round-trip times.
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 .\" .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
354 will report duplicate and damaged packets.
355 Duplicate packets should never occur when pinging a unicast address,
356 and seem to be caused by
357 inappropriate link-level retransmissions.
358 Duplicates may occur in many situations and are rarely
359 .Pq if ever
360 a good sign, although the presence of low levels of duplicates may not
361 always be cause for alarm.
362 Duplicates are expected when pinging a multicast address,
363 since they are not really duplicates but replies from different hosts
364 to the same request.
365 .Pp
366 Damaged packets are obviously serious cause for alarm and often
367 indicate broken hardware somewhere in the
368 .Nm
369 packet's path
370 .Pq in the network or in the hosts .
371 .Sh TRYING DIFFERENT DATA PATTERNS
372 The
373 (inter)network
374 layer should never treat packets differently depending on the data
375 contained in the data portion.
376 Unfortunately, data-dependent problems have been known to sneak into
377 networks and remain undetected for long periods of time.
378 In many cases the particular pattern that will have problems is something
379 that does not have sufficient
380 .Dq transitions ,
381 such as all ones or all zeros, or a pattern right at the edge, such as
382 almost all zeros.
383 It is not
384 necessarily enough to specify a data pattern of all zeros (for example)
385 on the command line because the pattern that is of interest is
386 at the data link level, and the relationship between what you type and
387 what the controllers transmit can be complicated.
388 .Pp
389 This means that if you have a data-dependent problem you will probably
390 have to do a lot of testing to find it.
391 If you are lucky, you may manage to find a file that either
392 cannot
393 be sent across your network or that takes much longer to transfer than
394 other similar length files.
395 You can then examine this file for repeated patterns that you can test
396 using the
397 .Fl p
398 option of
399 .Nm Ns .
400 .Sh EXIT STATUS
401 .Nm
402 exits with 0 on success (the host is alive),
403 and non-zero if the arguments are incorrect or the host is not responding.
404 .Sh EXAMPLES
405 Normally,
406 .Nm
407 works just like
408 .Xr ping 8
409 would work; the following will send ICMPv6 echo request to
410 .Li dst.foo.com .
411 .Bd -literal -offset indent
412 ping6 -n dst.foo.com
413 .Ed
414 .Pp
415 The following will probe hostnames for all nodes on the network link attached to
416 .Li wi0
417 interface.
418 The address
419 .Li ff02::1
420 is named the link-local all-node multicast address, and the packet would
421 reach every node on the network link.
422 .Bd -literal -offset indent
423 ping6 -w ff02::1%wi0
424 .Ed
425 .Pp
426 The following will probe addresses assigned to the destination node,
427 .Li dst.foo.com .
428 .Bd -literal -offset indent
429 ping6 -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
456 The
457 .Xr ping 8
458 command appeared in
459 .Bx 4.3 .
460 The
461 .Nm
462 command with IPv6 support first appeared in the WIDE Hydrangea IPv6
463 protocol stack kit.
464 .Sh BUGS
465 .\" except for bsdi
466 .Nm
467 is intentionally separate from
468 .Xr ping 8 .