ping6 - send ICMPv6 ECHO_REQUEST packets to network hosts
ping6 [-dfHnNqRtvwW] [-a addrtype] [-b bufsiz] [-c count]
[-h hoplimit] [-I interface] [-i wait] [-l preload]
[-S sourceaddr] [-s packetsize] [hops ...] host
ping6 uses the ICMPv6 protocol's mandatory ICMP6_ECHO_REQUEST datagram to
elicit an ICMP6_ECHO_REPLY from a host or gateway.
datagrams (``pings'') have an IPv6 header, and ICMPv6 header
documented in RFC 2463. The options are as follows:
Generate ICMPv6 Node Information Node Addresses
than echo-request. addrtype must be a string constructed of the
a requests unicast addresses from all of the
interfaces. If the character is omitted,
only those addresses
which belong to the interface which
has the responder's
address are requests.
c requests responder's IPv4-compatible and
g requests responder's global-scope addresses.
s requests responder's site-local addresses.
l requests responder's link-local addresses.
A requests responder's anycast addresses.
character, the responder will return unicast
only. With this character, the responder
anycast addresses only. Note that the specification does
not specify how to get responder's anycast
This is an experimental option.
Set socket buffer size.
Stop after sending (and receiving) count ECHO_RESPONSE packets.
-d Set the SO_DEBUG option on the socket being used.
-f Flood ping. Outputs packets as fast as they come
back or one
hundred times per second, whichever is more. For
ECHO_REQUEST sent a period ``.'' is printed, while
ECHO_REPLY received a backspace is printed. This
rapid display of how many packets are being dropped.
super-user may use this option. This can be very
hard on a net-
work and should be used with caution.
Specifies to use gateway as the next hop to the destination. The
gateway must be a neighbor of the sending node.
-H Specifies to try reverse-lookup of IPv6 addresses.
command does not try reverse-lookup unless the option is specified.
Set the IPv6 hoplimit.
Source packets with the given interface address.
This flag applies
if the ping destination is a multicast address, or link-local/site-local
Wait wait seconds between sending each packet. The
default is to
wait for one second between each packet. This option is incompatible
with the -f option.
If preload is specified, ping6 sends that many packets as fast as
possible before falling into its normal mode of behavior. Only
the super-user may use this option.
-n Numeric output only. No attempt will be made to
names from addresses in the reply.
-N Probe node information multicast group
must be string hostname of the target (must not be a
address). Node information multicast group will be
based on given host, and will be used as the final
Since node information multicast group is a link-local multicast
group, outgoing interface needs to be specified by
You may specify up to 16 ``pad'' bytes to fill out
the packet you
send. This is useful for diagnosing data-dependent
problems in a
network. For example, ``-p ff'' will cause the sent
packet to be
filled with all ones.
-q Quiet output. Nothing is displayed except the summary lines at
startup time and when finished.
-R Make the kernel believe that the target host (or the
first hop if
you specify hops) is reachable, by injecting upperlayer reachability
confirmation hint. The option is meaningful
only if the
target host (or the first hop) is a neighbor.
Specifies the source address of request packets.
The source address
must be one of the unicast addresses of the
and must be numeric.
Specifies the number of data bytes to be sent. The
56, which translates into 64 ICMP data bytes when
the 8 bytes of ICMP header data. You may need to
specify -b as
well to extend socket buffer size.
-t Generate ICMPv6 Node Information supported query
rather than echo-request. -s has no effect if -t is
-v Verbose output. ICMP packets other than ECHO_RESPONSE that are
received are listed.
-w Generate ICMPv6 Node Information DNS Name query,
echo-request. -s has no effect if -w is specified.
-W Same as -w, but with old packet format based on 03
option is present for backward compatibility. -s
has no effect
if -w is specified.
hops IPv6 addresses for intermediate nodes, which will be
type 0 routing header.
host IPv6 address of the final destination node.
When using ping6 for fault isolation, it should first be run
on the local
host, to verify that the local network interface is up and
Then, hosts and gateways further and further away should be
Round-trip times and packet loss statistics are computed.
packets are received, they are not included in the packet
although the round trip time of these packets is used
the round-trip time statistics. When the specified number of packets
have been sent (and received) or if the program is terminated with a
SIGINT, a brief summary is displayed, showing the number of
and received, and the minimum, maximum, mean, and standard
the round-trip times.
This program is intended for use in network testing, measurement and management.
Because of the load it can impose on the network,
it is unwise
to use ping6 during normal operations or from automated
DUPLICATE AND DAMAGED PACKETS [Toc] [Back]
ping6 will report duplicate and damaged packets. Duplicate
should never occur when pinging a unicast address, and seem
to be caused
by inappropriate link-level retransmissions. Duplicates may
many situations and are rarely (if ever) a good sign, although the presence
of low levels of duplicates may not always be cause for
are expected when pinging a broadcast or multicast
since they are not really duplicates but replies from different hosts to
the same request.
Damaged packets are obviously serious cause for alarm and
broken hardware somewhere in the ping6 packet's path (in the
in the hosts).
TRYING DIFFERENT DATA PATTERNS [Toc] [Back]
The (inter)network layer should never treat packets differently depending
on the data contained in the data portion. Unfortunately,
problems have been known to sneak into networks and remain
long periods of time. In many cases the particular pattern
have problems is something that does not have sufficient
such as all ones or all zeros, or a pattern right at the
edge, such as
almost all zeros. It is not necessarily enough to specify a
of all zeros (for example) on the command line because the
is of interest is at the data link level, and the relationship between
what you type and what the controllers transmit can be complicated.
This means that if you have a data-dependent problem you
have to do a lot of testing to find it. If you are lucky,
you may manage
to find a file that either cannot be sent across your network or that
takes much longer to transfer than other similar length
files. You can
then examine this file for repeated patterns that you can
test using the
-p option of ping6.
ping6 returns 0 on success (the host is alive), and non-zero
if the arguments
are incorrect or the host is not responding.
Normally, ping6 works just like ping(8) would work; the following will
send ICMPv6 echo request to dst.foo.com.
$ ping6 -n dst.foo.com
The following will probe hostnames for all nodes on the network link attached
to wi0 interface. The address ff02::1 is named the
all-node multicast address, and the packet would reach every
node on the
$ ping6 -w ff02::1%wi0
The following will probe addresses assigned to the destination node,
$ ping6 -a agl dst.foo.com
netstat(1), icmp6(4), inet6(4), ip6(4), ifconfig(8),
A. Conta and S. Deering, Internet Control Message Protocol
the Internet Protocol Version 6 (IPv6) Specification, RFC
Matt Crawford, IPv6 Node Information Queries, draft-ietf-ipngwg-icmpname-lookups-09.txt,
May 2002, work in progress material.
The ping(8) command appeared in 4.3BSD. The ping6 command
with IPv6 support
first appeared in the WIDE Hydrangea IPv6 protocol
ping6 is intentionally separate from ping(8).
OpenBSD 3.6 May 17, 1998
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