1 .\" $KAME: ping6.8,v 1.58 2003/06/20 12:00:22 itojun Exp $
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38 .Tn ICMPv6 ECHO_REQUEST
39 packets to network hosts
42 .\" without ipsec, or new ipsec
43 .Op Fl DdfHmnNoqrRtvwW
45 .\" .Op Fl ADdEfmnNqRtvwW
78 .Op Fl S Ar sourceaddr
81 .Op Fl s Ar packetsize
95 .Tn ICMP6_ECHO_REQUEST
98 from a host or gateway.
99 .Tn ICMP6_ECHO_REQUEST
100 datagrams (``pings'') have an IPv6 header,
103 header formatted as documented in RFC2463.
104 The options are as follows:
108 .\" Enables transport-mode IPsec authentication header
111 Generate ICMPv6 Node Information Node Addresses query, rather than echo-request.
113 must be a string constructed of the following characters.
114 .Bl -tag -width Ds -compact
116 requests unicast addresses from all of the responder's interfaces.
117 If the character is omitted,
118 only those addresses which belong to the interface which has the
119 responder's address are requests.
121 requests responder's IPv4-compatible and IPv4-mapped addresses.
123 requests responder's global-scope addresses.
125 requests responder's site-local addresses.
127 requests responder's link-local addresses.
129 requests responder's anycast addresses.
130 Without this character, the responder will return unicast addresses only.
131 With this character, the responder will return anycast addresses only.
132 Note that the specification does not specify how to get responder's
134 This is an experimental option.
137 Set socket buffer size.
145 Disable IPv6 fragmentation.
149 option on the socket being used.
151 .\" Enables transport-mode IPsec encapsulated security payload
155 Outputs packets as fast as they come back or one hundred times per second,
161 is printed, while for every
163 received a backspace is printed.
164 This provides a rapid display of how many packets are being dropped.
165 Only the super-user may use this option.
167 This can be very hard on a network and should be used with caution.
172 as the next hop to the destination.
173 The gateway must be a neighbor of the sending node.
175 Specifies to try reverse-lookup of IPv6 addresses.
178 utility does not try reverse-lookup unless the option is specified.
180 Set the IPv6 hoplimit.
181 .It Fl I Ar interface
182 Source packets with the given interface address.
183 This flag applies if the ping destination is a multicast address,
184 or link-local/site-local unicast address.
189 .Em between sending each packet .
190 The default is to wait for one second between each packet.
191 This option is incompatible with the
199 sends that many packets as fast as possible before falling into its normal
201 Only the super-user may use this option.
205 asks the kernel to fragment packets to fit into the minimum IPv6 MTU.
209 will suppress the behavior in the following two levels:
210 when the option is specified once, the behavior will be disabled for
212 When the option is more than once, it will be disabled for both
213 unicast and multicast packets.
216 No attempt will be made to lookup symbolic names from addresses in the reply.
218 Probe node information multicast group
219 .Pq Li ff02::2:xxxx:xxxx .
221 must be string hostname of the target
222 (must not be a numeric IPv6 address).
223 Node information multicast group will be computed based on given
225 and will be used as the final destination.
226 Since node information multicast group is a link-local multicast group,
227 outgoing interface needs to be specified by
231 Exit successfully after receiving one reply packet.
233 You may specify up to 16
235 bytes to fill out the packet you send.
236 This is useful for diagnosing data-dependent problems in a network.
239 will cause the sent packet to be filled with all
244 specifies IPsec policy to be used for the probe.
247 Nothing is displayed except the summary lines at startup time and
254 character in the output when any packet is received.
260 character when no packet is received before the next packet
262 To cater for round-trip times that are longer than the interval
263 between transmissions, further missing packets cause a bell only
264 if the maximum number of unreceived packets has increased.
265 .It Fl S Ar sourceaddr
266 Specifies the source address of request packets.
267 The source address must be one of the unicast addresses of the sending node,
269 .It Fl s Ar packetsize
270 Specifies the number of data bytes to be sent.
271 The default is 56, which translates into 64
273 data bytes when combined
277 You may need to specify
279 as well to extend socket buffer size.
281 Generate ICMPv6 Node Information supported query types query,
282 rather than echo-request.
292 that are received are listed.
294 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
302 but with old packet format based on 03 draft.
303 This option is present for backward compatibility.
309 IPv6 addresses for intermediate nodes,
310 which will be put into type 0 routing header.
312 IPv6 address of the final destination node.
317 for fault isolation, it should first be run on the local host, to verify
318 that the local network interface is up and running.
319 Then, hosts and gateways further and further away should be
321 Round-trip times and packet loss statistics are computed.
322 If duplicate packets are received, they are not included in the packet
323 loss calculation, although the round trip time of these packets is used
324 in calculating the round-trip time statistics.
325 When the specified number of packets have been sent
327 or if the program is terminated with a
329 a brief summary is displayed, showing the number of packets sent and
330 received, and the minimum, mean, maximum, and standard deviation of
331 the round-trip times.
341 signal, the current number of packets sent and received, and the
342 minimum, mean, maximum, and standard deviation of the round-trip times
343 will be written to the standard output in the same format as the
344 standard completion message.
346 This program is intended for use in network testing, measurement and
348 Because of the load it can impose on the network, it is unwise to use
350 during normal operations or from automated scripts.
351 .\" .Sh ICMP PACKET DETAILS
352 .\" An IP header without options is 20 bytes.
356 .\" packet contains an additional 8 bytes worth of
358 .\" header followed by an arbitrary amount of data.
361 .\" is given, this indicated the size of this extra piece of data
362 .\" (the default is 56).
363 .\" Thus the amount of data received inside of an IP packet of type
366 .\" will always be 8 bytes more than the requested data space
371 .\" If the data space is at least eight bytes large,
373 .\" uses the first eight bytes of this space to include a timestamp which
374 .\" it uses in the computation of round trip times.
375 .\" If less than eight bytes of pad are specified, no round trip times are
377 .Sh DUPLICATE AND DAMAGED PACKETS
380 utility will report duplicate and damaged packets.
381 Duplicate packets should never occur when pinging a unicast address,
382 and seem to be caused by
383 inappropriate link-level retransmissions.
384 Duplicates may occur in many situations and are rarely
386 a good sign, although the presence of low levels of duplicates may not
387 always be cause for alarm.
388 Duplicates are expected when pinging a broadcast or multicast address,
389 since they are not really duplicates but replies from different hosts
392 Damaged packets are obviously serious cause for alarm and often
393 indicate broken hardware somewhere in the
396 (in the network or in the hosts).
397 .Sh TRYING DIFFERENT DATA PATTERNS
400 layer should never treat packets differently depending on the data
401 contained in the data portion.
402 Unfortunately, data-dependent problems have been known to sneak into
403 networks and remain undetected for long periods of time.
404 In many cases the particular pattern that will have problems is something
405 that does not have sufficient
407 such as all ones or all zeros, or a pattern right at the edge, such as
410 necessarily enough to specify a data pattern of all zeros (for example)
411 on the command line because the pattern that is of interest is
412 at the data link level, and the relationship between what you type and
413 what the controllers transmit can be complicated.
415 This means that if you have a data-dependent problem you will probably
416 have to do a lot of testing to find it.
417 If you are lucky, you may manage to find a file that either
419 be sent across your network or that takes much longer to transfer than
420 other similar length files.
421 You can then examine this file for repeated patterns that you can test
429 utility returns 0 on success (the host is alive),
430 2 if the transmission was successful but no responses were received,
431 any other non-zero value if the arguments are incorrect or
432 another error has occurred.
438 would work; the following will send ICMPv6 echo request to
440 .Bd -literal -offset indent
444 The following will probe hostnames for all nodes on the network link attached to
449 is named the link-local all-node multicast address, and the packet would
450 reach every node on the network link.
451 .Bd -literal -offset indent
455 The following will probe addresses assigned to the destination node,
457 .Bd -literal -offset indent
458 ping6 -a agl dst.foo.com
473 .%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"
479 .%T "IPv6 Node Information Queries"
480 .%N draft-ietf-ipngwg-icmp-name-lookups-09.txt
482 .%O work in progress material
491 utility with IPv6 support first appeared in the WIDE Hydrangea IPv6
494 IPv6 and IPsec support based on the KAME Project
495 .Pq Pa http://www.kame.net/
496 stack was initially integrated into
502 is intentionally separate from
505 There have been many discussions on why we separate
509 Some people argued that it would be more convenient to uniform the
510 ping command for both IPv4 and IPv6.
511 The followings are an answer to the request.
513 From a developer's point of view:
514 since the underling raw sockets API is totally different between IPv4
515 and IPv6, we would end up having two types of code base.
516 There would actually be less benefit to uniform the two commands
517 into a single command from the developer's standpoint.
519 From an operator's point of view: unlike ordinary network applications
520 like remote login tools, we are usually aware of address family when using
521 network management tools.
522 We do not just want to know the reachability to the host, but want to know the
523 reachability to the host via a particular network protocol such as
525 Thus, even if we had a unified
527 command for both IPv4 and IPv6, we would usually type a
531 option (or something like those) to specify the particular address family.
532 This essentially means that we have two different commands.