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
45 .\" .Op Fl AdEfmnNqRtvwW
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.
147 option on the socket being used.
149 .\" Enables transport-mode IPsec encapsulated security payload
153 Outputs packets as fast as they come back or one hundred times per second,
159 is printed, while for every
161 received a backspace is printed.
162 This provides a rapid display of how many packets are being dropped.
163 Only the super-user may use this option.
165 This can be very hard on a network and should be used with caution.
170 as the next hop to the destination.
171 The gateway must be a neighbor of the sending node.
173 Specifies to try reverse-lookup of IPv6 addresses.
176 utility does not try reverse-lookup unless the option is specified.
178 Set the IPv6 hoplimit.
179 .It Fl I Ar interface
180 Source packets with the given interface address.
181 This flag applies if the ping destination is a multicast address,
182 or link-local/site-local unicast address.
187 .Em between sending each packet .
188 The default is to wait for one second between each packet.
189 This option is incompatible with the
197 sends that many packets as fast as possible before falling into its normal
199 Only the super-user may use this option.
203 asks the kernel to fragment packets to fit into the minimum IPv6 MTU.
207 will suppress the behavior in the following two levels:
208 when the option is specified once, the behavior will be disabled for
210 When the option is more than once, it will be disabled for both
211 unicast and multicast packets.
214 No attempt will be made to lookup symbolic names from addresses in the reply.
216 Probe node information multicast group
217 .Pq Li ff02::2:xxxx:xxxx .
219 must be string hostname of the target
220 (must not be a numeric IPv6 address).
221 Node information multicast group will be computed based on given
223 and will be used as the final destination.
224 Since node information multicast group is a link-local multicast group,
225 outgoing interface needs to be specified by
229 Exit successfully after receiving one reply packet.
231 You may specify up to 16
233 bytes to fill out the packet you send.
234 This is useful for diagnosing data-dependent problems in a network.
237 will cause the sent packet to be filled with all
242 specifies IPsec policy to be used for the probe.
245 Nothing is displayed except the summary lines at startup time and
252 character in the output when any packet is received.
258 character when no packet is received before the next packet
260 To cater for round-trip times that are longer than the interval
261 between transmissions, further missing packets cause a bell only
262 if the maximum number of unreceived packets has increased.
263 .It Fl S Ar sourceaddr
264 Specifies the source address of request packets.
265 The source address must be one of the unicast addresses of the sending node,
267 .It Fl s Ar packetsize
268 Specifies the number of data bytes to be sent.
269 The default is 56, which translates into 64
271 data bytes when combined
275 You may need to specify
277 as well to extend socket buffer size.
279 Generate ICMPv6 Node Information supported query types query,
280 rather than echo-request.
290 that are received are listed.
292 Generate ICMPv6 Node Information DNS Name query, rather than echo-request.
300 but with old packet format based on 03 draft.
301 This option is present for backward compatibility.
307 IPv6 addresses for intermediate nodes,
308 which will be put into type 0 routing header.
310 IPv6 address of the final destination node.
315 for fault isolation, it should first be run on the local host, to verify
316 that the local network interface is up and running.
317 Then, hosts and gateways further and further away should be
319 Round-trip times and packet loss statistics are computed.
320 If duplicate packets are received, they are not included in the packet
321 loss calculation, although the round trip time of these packets is used
322 in calculating the round-trip time statistics.
323 When the specified number of packets have been sent
325 or if the program is terminated with a
327 a brief summary is displayed, showing the number of packets sent and
328 received, and the minimum, mean, maximum, and standard deviation of
329 the round-trip times.
339 signal, the current number of packets sent and received, and the
340 minimum, mean, maximum, and standard deviation of the round-trip times
341 will be written to the standard output in the same format as the
342 standard completion message.
344 This program is intended for use in network testing, measurement and
346 Because of the load it can impose on the network, it is unwise to use
348 during normal operations or from automated scripts.
349 .\" .Sh ICMP PACKET DETAILS
350 .\" An IP header without options is 20 bytes.
354 .\" packet contains an additional 8 bytes worth of
356 .\" header followed by an arbitrary amount of data.
359 .\" is given, this indicated the size of this extra piece of data
360 .\" (the default is 56).
361 .\" Thus the amount of data received inside of an IP packet of type
364 .\" will always be 8 bytes more than the requested data space
369 .\" If the data space is at least eight bytes large,
371 .\" uses the first eight bytes of this space to include a timestamp which
372 .\" it uses in the computation of round trip times.
373 .\" If less than eight bytes of pad are specified, no round trip times are
375 .Sh DUPLICATE AND DAMAGED PACKETS
378 utility will report duplicate and damaged packets.
379 Duplicate packets should never occur when pinging a unicast address,
380 and seem to be caused by
381 inappropriate link-level retransmissions.
382 Duplicates may occur in many situations and are rarely
384 a good sign, although the presence of low levels of duplicates may not
385 always be cause for alarm.
386 Duplicates are expected when pinging a broadcast or multicast address,
387 since they are not really duplicates but replies from different hosts
390 Damaged packets are obviously serious cause for alarm and often
391 indicate broken hardware somewhere in the
394 (in the network or in the hosts).
395 .Sh TRYING DIFFERENT DATA PATTERNS
398 layer should never treat packets differently depending on the data
399 contained in the data portion.
400 Unfortunately, data-dependent problems have been known to sneak into
401 networks and remain undetected for long periods of time.
402 In many cases the particular pattern that will have problems is something
403 that does not have sufficient
405 such as all ones or all zeros, or a pattern right at the edge, such as
408 necessarily enough to specify a data pattern of all zeros (for example)
409 on the command line because the pattern that is of interest is
410 at the data link level, and the relationship between what you type and
411 what the controllers transmit can be complicated.
413 This means that if you have a data-dependent problem you will probably
414 have to do a lot of testing to find it.
415 If you are lucky, you may manage to find a file that either
417 be sent across your network or that takes much longer to transfer than
418 other similar length files.
419 You can then examine this file for repeated patterns that you can test
427 utility returns 0 on success (the host is alive),
428 2 if the transmission was successful but no responses were received,
429 any other non-zero value if the arguments are incorrect or
430 another error has occured.
436 would work; the following will send ICMPv6 echo request to
438 .Bd -literal -offset indent
442 The following will probe hostnames for all nodes on the network link attached to
447 is named the link-local all-node multicast address, and the packet would
448 reach every node on the network link.
449 .Bd -literal -offset indent
453 The following will probe addresses assigned to the destination node,
455 .Bd -literal -offset indent
456 ping6 -a agl dst.foo.com
471 .%T "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"
477 .%T "IPv6 Node Information Queries"
478 .%N draft-ietf-ipngwg-icmp-name-lookups-09.txt
480 .%O work in progress material
489 utility with IPv6 support first appeared in the WIDE Hydrangea IPv6
492 IPv6 and IPsec support based on the KAME Project
493 .Pq Pa http://www.kame.net/
494 stack was initially integrated into
500 is intentionally separate from
503 There have been many discussions on why we separate
507 Some people argued that it would be more convenient to uniform the
508 ping command for both IPv4 and IPv6.
509 The followings are an answer to the request.
511 From a developer's point of view:
512 since the underling raw sockets API is totally different between IPv4
513 and IPv6, we would end up having two types of code base.
514 There would actually be less benefit to uniform the two commands
515 into a single command from the developer's standpoint.
517 From an operator's point of view: unlike ordinary network applications
518 like remote login tools, we are usually aware of address family when using
519 network management tools.
520 We do not just want to know the reachability to the host, but want to know the
521 reachability to the host via a particular network protocol such as
523 Thus, even if we had a unified
525 command for both IPv4 and IPv6, we would usually type a
529 option (or something like those) to specify the particular address family.
530 This essentially means that we have two different commands.