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 aAdDfHnNoOquvyY
45 .\" .Op Fl ADdEfmnNqRtvwW
78 .Op Fl S Ar sourceaddr
81 .Op Fl s Ar packetsize
101 .Tn ICMP6_ECHO_REQUEST
102 datagram to elicit an
104 from a host or gateway.
105 .Tn ICMP6_ECHO_REQUEST
106 datagrams (``pings'') have an IPv6 header,
109 header formatted as documented in RFC2463.
110 The options are as follows:
114 .\" Enables transport-mode IPsec authentication header
117 Generate ICMPv6 Node Information Node Addresses query, rather than echo-request.
119 must be a string constructed of the following characters.
120 .Bl -tag -width Ds -compact
122 requests unicast addresses from all of the responder's interfaces.
123 If the character is omitted,
124 only those addresses which belong to the interface which has the
125 responder's address are requests.
127 requests responder's IPv4-compatible and IPv4-mapped addresses.
129 requests responder's global-scope addresses.
131 requests responder's site-local addresses.
133 requests responder's link-local addresses.
135 requests responder's anycast addresses.
136 Without this character, the responder will return unicast addresses only.
137 With this character, the responder will return anycast addresses only.
138 Note that the specification does not specify how to get responder's
140 This is an experimental option.
143 Set socket buffer size.
151 Disable IPv6 fragmentation.
155 option on the socket being used.
157 .\" Enables transport-mode IPsec encapsulated security payload
161 Outputs packets as fast as they come back or one hundred times per second,
167 is printed, while for every
169 received a backspace is printed.
170 This provides a rapid display of how many packets are being dropped.
171 Only the super-user may use this option.
173 This can be very hard on a network and should be used with caution.
178 as the next hop to the destination.
179 The gateway must be a neighbor of the sending node.
181 Specifies to try reverse-lookup of IPv6 addresses.
184 utility does not try reverse-lookup unless the option is specified.
186 Set the IPv6 hoplimit.
187 .It Fl I Ar interface
188 Source packets with the given interface address.
189 This flag applies if the ping destination is a multicast address,
190 or link-local/site-local unicast address.
195 .Em between sending each packet .
196 The default is to wait for one second between each packet.
197 This option is incompatible with the
201 Time in milliseconds to wait for a reply for each packet sent.
202 If a reply arrives later,
203 the packet is not printed as replied,
204 but considered as replied when calculating statistics.
208 before ping exits regardless of how many packets have been received.
214 sends that many packets as fast as possible before falling into its normal
216 Only the super-user may use this option.
220 asks the kernel to fragment packets to fit into the minimum IPv6 MTU.
224 will suppress the behavior in the following two levels:
225 when the option is specified once, the behavior will be disabled for
227 When the option is more than once, it will be disabled for both
228 unicast and multicast packets.
231 No attempt will be made to lookup symbolic names from addresses in the reply.
233 Probe node information multicast group address
234 .Pq Li ff02::2:ffxx:xxxx .
236 must be string hostname of the target
237 (must not be a numeric IPv6 address).
238 Node information multicast group will be computed based on given
240 and will be used as the final destination.
241 Since node information multicast group is a link-local multicast group,
242 outgoing interface needs to be specified by
246 When specified twice, the address
247 .Pq Li ff02::2:xxxx:xxxx
249 The former is in RFC 4620, the latter is in an old Internet Draft
250 draft-ietf-ipngwg-icmp-name-lookup.
251 Note that KAME-derived implementations including
255 Exit successfully after receiving one reply packet.
257 You may specify up to 16
259 bytes to fill out the packet you send.
260 This is useful for diagnosing data-dependent problems in a network.
263 will cause the sent packet to be filled with all
268 specifies IPsec policy to be used for the probe.
271 Nothing is displayed except the summary lines at startup time and
278 character in the output when any packet is received.
284 character when no packet is received before the next packet
286 To cater for round-trip times that are longer than the interval
287 between transmissions, further missing packets cause a bell only
288 if the maximum number of unreceived packets has increased.
289 .It Fl S Ar sourceaddr
290 Specifies the source address of request packets.
291 The source address must be one of the unicast addresses of the sending node,
293 .It Fl s Ar packetsize
294 Specifies the number of data bytes to be sent.
295 The default is 56, which translates into 64
297 data bytes when combined
301 You may need to specify
303 as well to extend socket buffer size.
305 Generate ICMPv6 Node Information supported query types query,
306 rather than echo-request.
316 that are received are listed.
318 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
326 but with old packet format based on 03 draft.
327 This option is present for backward compatibility.
333 IPv6 addresses for intermediate nodes,
334 which will be put into type 0 routing header.
336 IPv6 address of the final destination node.
341 for fault isolation, it should first be run on the local host, to verify
342 that the local network interface is up and running.
343 Then, hosts and gateways further and further away should be
345 Round-trip times and packet loss statistics are computed.
346 If duplicate packets are received, they are not included in the packet
347 loss calculation, although the round trip time of these packets is used
348 in calculating the round-trip time statistics.
349 When the specified number of packets have been sent
351 or if the program is terminated with a
353 a brief summary is displayed, showing the number of packets sent and
354 received, and the minimum, mean, maximum, and standard deviation of
355 the round-trip times.
365 signal, the current number of packets sent and received, and the
366 minimum, mean, maximum, and standard deviation of the round-trip times
367 will be written to the standard output in the same format as the
368 standard completion message.
370 This program is intended for use in network testing, measurement and
372 Because of the load it can impose on the network, it is unwise to use
374 during normal operations or from automated scripts.
375 .\" .Sh ICMP PACKET DETAILS
376 .\" An IP header without options is 20 bytes.
380 .\" packet contains an additional 8 bytes worth of
382 .\" header followed by an arbitrary amount of data.
385 .\" is given, this indicated the size of this extra piece of data
386 .\" (the default is 56).
387 .\" Thus the amount of data received inside of an IP packet of type
390 .\" will always be 8 bytes more than the requested data space
395 .\" If the data space is at least eight bytes large,
397 .\" uses the first eight bytes of this space to include a timestamp which
398 .\" it uses in the computation of round trip times.
399 .\" If less than eight bytes of pad are specified, no round trip times are
401 .Sh DUPLICATE AND DAMAGED PACKETS
404 utility will report duplicate and damaged packets.
405 Duplicate packets should never occur when pinging a unicast address,
406 and seem to be caused by
407 inappropriate link-level retransmissions.
408 Duplicates may occur in many situations and are rarely
410 a good sign, although the presence of low levels of duplicates may not
411 always be cause for alarm.
412 Duplicates are expected when pinging a broadcast or multicast address,
413 since they are not really duplicates but replies from different hosts
416 Damaged packets are obviously serious cause for alarm and often
417 indicate broken hardware somewhere in the
420 (in the network or in the hosts).
421 .Sh TRYING DIFFERENT DATA PATTERNS
424 layer should never treat packets differently depending on the data
425 contained in the data portion.
426 Unfortunately, data-dependent problems have been known to sneak into
427 networks and remain undetected for long periods of time.
428 In many cases the particular pattern that will have problems is something
429 that does not have sufficient
431 such as all ones or all zeros, or a pattern right at the edge, such as
434 necessarily enough to specify a data pattern of all zeros (for example)
435 on the command line because the pattern that is of interest is
436 at the data link level, and the relationship between what you type and
437 what the controllers transmit can be complicated.
439 This means that if you have a data-dependent problem you will probably
440 have to do a lot of testing to find it.
441 If you are lucky, you may manage to find a file that either
443 be sent across your network or that takes much longer to transfer than
444 other similar length files.
445 You can then examine this file for repeated patterns that you can test
453 utility returns 0 on success (the host is alive),
454 2 if the transmission was successful but no responses were received,
455 any other non-zero value if the arguments are incorrect or
456 another error has occurred.
462 would work; the following will send ICMPv6 echo request to
464 .Bd -literal -offset indent
468 The following will probe hostnames for all nodes on the network link attached to
473 is named the link-local all-node multicast address, and the packet would
474 reach every node on the network link.
475 .Bd -literal -offset indent
479 The following will probe addresses assigned to the destination node,
481 .Bd -literal -offset indent
482 ping6 -k agl dst.foo.com
497 .%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"
503 .%T "IPv6 Node Information Queries"
504 .%N draft-ietf-ipngwg-icmp-name-lookups-09.txt
506 .%O work in progress material
515 utility with IPv6 support first appeared in the WIDE Hydrangea IPv6
518 IPv6 and IPsec support based on the KAME Project
519 .Pq Pa http://www.kame.net/
520 stack was initially integrated into
526 is intentionally separate from
529 There have been many discussions on why we separate
533 Some people argued that it would be more convenient to uniform the
534 ping command for both IPv4 and IPv6.
535 The followings are an answer to the request.
537 From a developer's point of view:
538 since the underling raw sockets API is totally different between IPv4
539 and IPv6, we would end up having two types of code base.
540 There would actually be less benefit to uniform the two commands
541 into a single command from the developer's standpoint.
543 From an operator's point of view: unlike ordinary network applications
544 like remote login tools, we are usually aware of address family when using
545 network management tools.
546 We do not just want to know the reachability to the host, but want to know the
547 reachability to the host via a particular network protocol such as
549 Thus, even if we had a unified
551 command for both IPv4 and IPv6, we would usually type a
555 option (or something like those) to specify the particular address family.
556 This essentially means that we have two different commands.