PING6(8) BSD System Manager's Manual PING6(8)
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 da-
tagrams (``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 ad-
dresses which belong to the interface which has the
responder's address are requests.
c requests responder's IPv4-compatible and IPv4-mapped ad-
dresses.
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 any-
cast 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 hun-
dred 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 op-
tion. This can be very hard on a network 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 com-
mand 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 ap-
plies 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 incompa-
tible 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
upper-layer reachability confirmation hint. The option is mean-
ingful only if the target host (or the first hop) is a neighbor.
-S sourceaddr
Specifies the source address of request packets. The source ad-
dress 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 re-
ceived, 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 un-
wise to use ping6 during normal operations or from automated scripts.
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).
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 argu-
ments 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 at-
tached 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 net-
work 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-icmp-
name-lookups-09.txt, May 2002, work in progress material.
The ping(8) command appeared in 4.3BSD. The ping6 command with IPv6 sup-
port first appeared in the WIDE Hydrangea IPv6 protocol stack kit.
ping6 is intentionally separate from ping(8).
MirBSD #10-current May 17, 1998 3