-4
Use IPv4 only.
-6
Use IPv6 only.
-a
Audible ping.
-A
Adaptive ping. Interpacket interval adapts to round-trip
time, so that effectively not more than one (or more, if
preload is set) unanswered probe is present in the network.
Minimal interval is 200msec unless super-user. On networks
with low RTT this mode is essentially equivalent to flood
mode.
-b
Allow pinging a broadcast address.
-B
Do not allow ping to change source address of probes. The
address is bound to one selected when ping starts.
-c count
Stop after sending count ECHO_REQUEST packets. With deadline
option, ping waits for count ECHO_REPLY packets, until the
timeout expires.
-d
Set the SO_DEBUG option on the socket being used.
Essentially, this socket option is not used by Linux kernel.
-D
Print timestamp (unix time + microseconds as in gettimeofday)
before each line.
-f
Flood ping. 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. If interval is not given, it sets interval
to zero and outputs packets as fast as they come back or one
hundred times per second, whichever is more. Only the
super-user may use this option with zero interval.
-F flow label
IPv6 only. Allocate and set 20 bit flow label (in hex) on
echo request packets. If value is zero, kernel allocates
random flow label.
-h
Show help.
-i interval
Wait interval seconds between sending each packet. Real
number allowed with dot as a decimal separator (regardless
locale setup). The default is to wait for one second between
each packet normally, or not to wait in flood mode. Only
super-user may set interval to values less than 0.2 seconds.
-I interface
interface is either an address, an interface name or a VRF
name. If interface is an address, it sets source address to
specified interface address. If interface is an interface
name, it sets source interface to specified interface. If
interface is a VRF name, each packet is routed using the
corresponding routing table; in this case, the -I option can
be repeated to specify a source address. NOTE: For IPv6, when
doing ping to a link-local scope address, link specification
(by the '%'-notation in destination, or by this option) can
be used but it is no longer required.
-l preload
If preload is specified, ping sends that many packets not
waiting for reply. Only the super-user may select preload
more than 3.
-L
Suppress loopback of multicast packets. This flag only
applies if the ping destination is a multicast address.
-m mark
use mark to tag the packets going out. This is useful for
variety of reasons within the kernel such as using policy
routing to select specific outbound processing.
-M pmtudisc_opt
Select Path MTU Discovery strategy. pmtudisc_option may be
either do (prohibit fragmentation, even local one), want (do
PMTU discovery, fragment locally when packet size is large),
or dont (do not set DF flag).
-N nodeinfo_option
IPv6 only. Send ICMPv6 Node Information Queries (RFC4620),
instead of Echo Request. CAP_NET_RAW capability is required.
help
Show help for NI support.
name
Queries for Node Names.
ipv6
Queries for IPv6 Addresses. There are several IPv6
specific flags.
ipv6-global
Request IPv6 global-scope addresses.
ipv6-sitelocal
Request IPv6 site-local addresses.
ipv6-linklocal
Request IPv6 link-local addresses.
ipv6-all
Request IPv6 addresses on other interfaces.
ipv4
Queries for IPv4 Addresses. There is one IPv4 specific
flag.
ipv4-all
Request IPv4 addresses on other interfaces.
subject-ipv6=ipv6addr
IPv6 subject address.
subject-ipv4=ipv4addr
IPv4 subject address.
subject-name=nodename
Subject name. If it contains more than one dot,
fully-qualified domain name is assumed.
subject-fqdn=nodename
Subject name. Fully-qualified domain name is always
assumed.
-n
Numeric output only. No attempt will be made to lookup
symbolic names for host addresses.
-O
Report outstanding ICMP ECHO reply before sending next
packet. This is useful together with the timestamp -D to log
output to a diagnostic file and search for missing answers.
-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.
-Q tos
Set Quality of Service -related bits in ICMP datagrams. tos
can be decimal (ping only) or hex number.
In RFC2474, these fields are interpreted as 8-bit
Differentiated Services (DS), consisting of: bits 0-1 (2
lowest bits) of separate data, and bits 2-7 (highest 6 bits)
of Differentiated Services Codepoint (DSCP). In RFC2481 and
RFC3168, bits 0-1 are used for ECN.
Historically (RFC1349, obsoleted by RFC2474), these were
interpreted as: bit 0 (lowest bit) for reserved (currently
being redefined as congestion control), 1-4 for Type of
Service and bits 5-7 (highest bits) for Precedence.
-r
Bypass the normal routing tables and send directly to a host
on an attached interface. If the host is not on a
directly-attached network, an error is returned. This option
can be used to ping a local host through an interface that
has no route through it provided the option -I is also used.
-R
ping only. Record route. Includes the RECORD_ROUTE option in
the ECHO_REQUEST packet and displays the route buffer on
returned packets. Note that the IP header is only large
enough for nine such routes. Many hosts ignore or discard
this option.
-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.
-S sndbuf
Set socket sndbuf. If not specified, it is selected to buffer
not more than one packet.
-t ttl
ping only. Set the IP Time to Live.
-T timestamp option
Set special IP timestamp options. timestamp option may be
either tsonly (only timestamps), tsandaddr (timestamps and
addresses) or tsprespec host1 [host2 [host3 [host4]]]
(timestamp prespecified hops).
-U
Print full user-to-user latency (the old behaviour). Normally
ping prints network round trip time, which can be different
f.e. due to DNS failures.
-v
Verbose output. Do not suppress DUP replies when pinging
multicast address.
-V
Show version and exit.
-w deadline
Specify a timeout, in seconds, before ping exits regardless
of how many packets have been sent or received. In this case
ping does not stop after count packet are sent, it waits
either for deadline expire or until count probes are answered
or for some error notification from network.
-W timeout
Time to wait for a response, in seconds. The option affects
only timeout in absence of any responses, otherwise ping
waits for two RTTs. Real number allowed with dot as a decimal
separator (regardless locale setup). 0 means infinite
timeout.
When using ping 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
minimum/average/maximum/mdev round-trip time numbers.
Population standard deviation (mdev), essentially an average of
how far each ping RTT is from the mean RTT. The higher mdev is,
the more variable the RTT is (over time). With a high RTT
variability, you will have speed issues with bulk transfers (they
will take longer than is strictly speaking necessary, as the
variability will eventually cause the sender to wait for ACKs)
and you will have middling to poor VoIP quality.
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. Shorter current statistics can be obtained
without termination of process with signal SIGQUIT.
If ping does not receive any reply packets at all it will exit
with code 1. If a packet count and deadline are both specified,
and fewer than count packets are received by the time the
deadline has arrived, it will also exit with code 1. On other
error it exits with code 2. Otherwise it exits with code 0. This
makes it possible to use the exit code to see if a host is alive
or not.
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 ping during normal operations or from
automated scripts.
