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 address
219 .Pq Li ff02::2:ffxx: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 When specified twice, the address
232 .Pq Li ff02::2:xxxx:xxxx
234 The former is in RFC 4620, the latter is in an old Internet Draft
235 draft-ietf-ipngwg-icmp-name-lookup.
236 Note that KAME-derived implementations including
240 Exit successfully after receiving one reply packet.
242 You may specify up to 16
244 bytes to fill out the packet you send.
245 This is useful for diagnosing data-dependent problems in a network.
248 will cause the sent packet to be filled with all
253 specifies IPsec policy to be used for the probe.
256 Nothing is displayed except the summary lines at startup time and
263 character in the output when any packet is received.
269 character when no packet is received before the next packet
271 To cater for round-trip times that are longer than the interval
272 between transmissions, further missing packets cause a bell only
273 if the maximum number of unreceived packets has increased.
274 .It Fl S Ar sourceaddr
275 Specifies the source address of request packets.
276 The source address must be one of the unicast addresses of the sending node,
278 .It Fl s Ar packetsize
279 Specifies the number of data bytes to be sent.
280 The default is 56, which translates into 64
282 data bytes when combined
286 You may need to specify
288 as well to extend socket buffer size.
290 Generate ICMPv6 Node Information supported query types query,
291 rather than echo-request.
301 that are received are listed.
303 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
311 but with old packet format based on 03 draft.
312 This option is present for backward compatibility.
318 IPv6 addresses for intermediate nodes,
319 which will be put into type 0 routing header.
321 IPv6 address of the final destination node.
326 for fault isolation, it should first be run on the local host, to verify
327 that the local network interface is up and running.
328 Then, hosts and gateways further and further away should be
330 Round-trip times and packet loss statistics are computed.
331 If duplicate packets are received, they are not included in the packet
332 loss calculation, although the round trip time of these packets is used
333 in calculating the round-trip time statistics.
334 When the specified number of packets have been sent
336 or if the program is terminated with a
338 a brief summary is displayed, showing the number of packets sent and
339 received, and the minimum, mean, maximum, and standard deviation of
340 the round-trip times.
350 signal, the current number of packets sent and received, and the
351 minimum, mean, maximum, and standard deviation of the round-trip times
352 will be written to the standard output in the same format as the
353 standard completion message.
355 This program is intended for use in network testing, measurement and
357 Because of the load it can impose on the network, it is unwise to use
359 during normal operations or from automated scripts.
360 .\" .Sh ICMP PACKET DETAILS
361 .\" An IP header without options is 20 bytes.
365 .\" packet contains an additional 8 bytes worth of
367 .\" header followed by an arbitrary amount of data.
370 .\" is given, this indicated the size of this extra piece of data
371 .\" (the default is 56).
372 .\" Thus the amount of data received inside of an IP packet of type
375 .\" will always be 8 bytes more than the requested data space
380 .\" If the data space is at least eight bytes large,
382 .\" uses the first eight bytes of this space to include a timestamp which
383 .\" it uses in the computation of round trip times.
384 .\" If less than eight bytes of pad are specified, no round trip times are
386 .Sh DUPLICATE AND DAMAGED PACKETS
389 utility will report duplicate and damaged packets.
390 Duplicate packets should never occur when pinging a unicast address,
391 and seem to be caused by
392 inappropriate link-level retransmissions.
393 Duplicates may occur in many situations and are rarely
395 a good sign, although the presence of low levels of duplicates may not
396 always be cause for alarm.
397 Duplicates are expected when pinging a broadcast or multicast address,
398 since they are not really duplicates but replies from different hosts
401 Damaged packets are obviously serious cause for alarm and often
402 indicate broken hardware somewhere in the
405 (in the network or in the hosts).
406 .Sh TRYING DIFFERENT DATA PATTERNS
409 layer should never treat packets differently depending on the data
410 contained in the data portion.
411 Unfortunately, data-dependent problems have been known to sneak into
412 networks and remain undetected for long periods of time.
413 In many cases the particular pattern that will have problems is something
414 that does not have sufficient
416 such as all ones or all zeros, or a pattern right at the edge, such as
419 necessarily enough to specify a data pattern of all zeros (for example)
420 on the command line because the pattern that is of interest is
421 at the data link level, and the relationship between what you type and
422 what the controllers transmit can be complicated.
424 This means that if you have a data-dependent problem you will probably
425 have to do a lot of testing to find it.
426 If you are lucky, you may manage to find a file that either
428 be sent across your network or that takes much longer to transfer than
429 other similar length files.
430 You can then examine this file for repeated patterns that you can test
438 utility returns 0 on success (the host is alive),
439 2 if the transmission was successful but no responses were received,
440 any other non-zero value if the arguments are incorrect or
441 another error has occurred.
447 would work; the following will send ICMPv6 echo request to
449 .Bd -literal -offset indent
453 The following will probe hostnames for all nodes on the network link attached to
458 is named the link-local all-node multicast address, and the packet would
459 reach every node on the network link.
460 .Bd -literal -offset indent
464 The following will probe addresses assigned to the destination node,
466 .Bd -literal -offset indent
467 ping6 -a agl dst.foo.com
482 .%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"
488 .%T "IPv6 Node Information Queries"
489 .%N draft-ietf-ipngwg-icmp-name-lookups-09.txt
491 .%O work in progress material
500 utility with IPv6 support first appeared in the WIDE Hydrangea IPv6
503 IPv6 and IPsec support based on the KAME Project
504 .Pq Pa http://www.kame.net/
505 stack was initially integrated into
511 is intentionally separate from
514 There have been many discussions on why we separate
518 Some people argued that it would be more convenient to uniform the
519 ping command for both IPv4 and IPv6.
520 The followings are an answer to the request.
522 From a developer's point of view:
523 since the underling raw sockets API is totally different between IPv4
524 and IPv6, we would end up having two types of code base.
525 There would actually be less benefit to uniform the two commands
526 into a single command from the developer's standpoint.
528 From an operator's point of view: unlike ordinary network applications
529 like remote login tools, we are usually aware of address family when using
530 network management tools.
531 We do not just want to know the reachability to the host, but want to know the
532 reachability to the host via a particular network protocol such as
534 Thus, even if we had a unified
536 command for both IPv4 and IPv6, we would usually type a
540 option (or something like those) to specify the particular address family.
541 This essentially means that we have two different commands.