ping6 - send ICMPv6 ECHO_REQUEST packets to network hosts
ping6 [-dfHnNqRtvwW] [-a addrtype] [-b bufsiz] [-c count]
[-g gateway]
[-h hoplimit] [-I interface] [-i wait] [-l preload]
[-p pattern]
[-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.
ICMP6_ECHO_REQUEST
datagrams (``pings'') have an IPv6 header, and ICMPv6 header
formatted as
documented in RFC 2463. The options are as follows:
-a addrtype
Generate ICMPv6 Node Information Node Addresses
query, rather
than echo-request. addrtype must be a string constructed of the
following characters.
a requests unicast addresses from all of the
responder's
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
IPv4-mapped addresses.
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.
Without this
character, the responder will return unicast
addresses
only. With this character, the responder
will return
anycast addresses only. Note that the specification does
not specify how to get responder's anycast
addresses.
This is an experimental option.
-b bufsiz
Set socket buffer size.
-c count
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
every
ECHO_REQUEST sent a period ``.'' is printed, while
for every
ECHO_REPLY received a backspace is printed. This
provides a
rapid display of how many packets are being dropped.
Only the
super-user may use this option. This can be very
hard on a net-
work and should be used with caution.
-g gateway
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.
The ping6
command does not try reverse-lookup unless the option is specified.
-h hoplimit
Set the IPv6 hoplimit.
-I interface
Source packets with the given interface address.
This flag applies
if the ping destination is a multicast address, or link-local/site-local
unicast address.
-i wait
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.
-l preload
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
lookup symbolic
names from addresses in the reply.
-N Probe node information multicast group
(ff02::2:xxxx:xxxx). host
must be string hostname of the target (must not be a
numeric IPv6
address). Node information multicast group will be
computed
based on given host, and will be used as the final
destination.
Since node information multicast group is a link-local multicast
group, outgoing interface needs to be specified by
-I option.
-p pattern
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.
-S sourceaddr
Specifies the source address of request packets.
The source address
must be one of the unicast addresses of the
sending node,
and must be numeric.
-s packetsize
Specifies the number of data bytes to be sent. The
default is
56, which translates into 64 ICMP data bytes when
combined with
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
types query,
rather than echo-request. -s has no effect if -t is
specified.
-v Verbose output. ICMP packets other than ECHO_RESPONSE that are
received are listed.
-w Generate ICMPv6 Node Information DNS Name query,
rather than
echo-request. -s has no effect if -w is specified.
-W Same as -w, but with old packet format based on 03
draft. This
option is present for backward compatibility. -s
has no effect
if -w is specified.
hops IPv6 addresses for intermediate nodes, which will be
put into
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
running.
Then, hosts and gateways further and further away should be
``pinged''.
Round-trip times and packet loss statistics are computed.
If duplicate
packets are received, they are not included in the packet
loss calculation,
although the round trip time of these packets is used
in calculating
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
packets sent
and received, and the minimum, maximum, mean, and standard
deviation of
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
scripts.
DUPLICATE AND DAMAGED PACKETS [Toc] [Back] ping6 will report duplicate and damaged packets. Duplicate
packets
should never occur when pinging a unicast address, and seem
to be caused
by inappropriate link-level retransmissions. Duplicates may
occur in
many situations and are rarely (if ever) a good sign, although the presence
of low levels of duplicates may not always be cause for
alarm. Duplicates
are expected when pinging a broadcast or multicast
address,
since they are not really duplicates but replies from different hosts to
the same request.
Damaged packets are obviously serious cause for alarm and
often indicate
broken hardware somewhere in the ping6 packet's path (in the
network or
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,
data-dependent
problems have been known to sneak into networks and remain
undetected for
long periods of time. In many cases the particular pattern
that will
have problems is something that does not have sufficient
``transitions'',
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
data pattern
of all zeros (for example) on the command line because the
pattern that
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
will probably
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
link-local
all-node multicast address, and the packet would reach every
node on the
network link.
$ ping6 -w ff02::1%wi0
The following will probe addresses assigned to the destination node,
dst.foo.com.
$ ping6 -a agl dst.foo.com
netstat(1), icmp6(4), inet6(4), ip6(4), ifconfig(8),
ping(8), routed(8),
traceroute(8), traceroute6(8)
A. Conta and S. Deering, Internet Control Message Protocol
(ICMPv6) for
the Internet Protocol Version 6 (IPv6) Specification, RFC
2463, December
1998.
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
stack kit.
ping6 is intentionally separate from ping(8).
OpenBSD 3.6 May 17, 1998
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