PING(8)                      System Manager's Manual                     PING(8)

     ping – send ICMP ECHO_REQUEST packets to network hosts

     ping [-AaCDdfnoQqRrv] [-b boundif] [-c count] [-G sweepmaxsize]
          [-g sweepminsize] [-h sweepincrsize] [-i wait] [-k trafficclass]
          [-K netservicetype] [-l preload] [-M mask | time] [-m ttl] [-P policy]
          [-p pattern] [-S src_addr] [-s packetsize] [-t timeout] [-W waittime]
          [-z tos] [--apple-connect] [--apple-time] host
     ping [-AaDdfLnoQqRrv] [-b boundif] [-c count] [-I iface] [-i wait]
          [-k trafficclass] [-K netservicetype] [-l preload] [-M mask | time]
          [-m ttl] [-P policy] [-p pattern] [-S src_addr] [-s packetsize]
          [-T ttl] [-t timeout] [-W waittime] [-z tos] [--apple-connect]
          [--apple-time] mcast-group

     The ping utility uses the ICMP protocol's mandatory ECHO_REQUEST datagram
     to elicit an ICMP ECHO_RESPONSE from a host or gateway.  ECHO_REQUEST
     datagrams (“pings”) have an IP and ICMP header, followed by a “struct
     timeval” and then an arbitrary number of “pad” bytes used to fill out the
     packet.  The options are as follows:

     -A      Audible.  Output a bell (ASCII 0x07) character when no packet is
             received before the next packet is transmitted.  To cater for
             round-trip times that are longer than the interval between
             transmissions, further missing packets cause a bell only if the
             maximum number of unreceived packets has increased.

     -a      Audible.  Include a bell (ASCII 0x07) character in the output when
             any packet is received.  This option is ignored if other format
             options are present.

     -b boundif
             Bind the socket to interface boundif for sending.  This option is
             an Apple addition.

     -C      Prohibit the socket from using the cellular network interface.
             This option is an Apple addition.

     -c count
             Stop after sending (and receiving) count ECHO_RESPONSE packets.  If
             this option is not specified, ping will operate until interrupted.
             If this option is specified in conjunction with ping sweeps, each
             sweep will consist of count packets.

     -D      Set the Don't Fragment bit.

     -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 network and should
             be used with caution.

     -G sweepmaxsize
             Specify the maximum size of ICMP payload when sending sweeping
             pings.  This option is required for ping sweeps.

     -g sweepminsize
             Specify the size of ICMP payload to start with when sending
             sweeping pings.  The default value is 0.

     -h sweepincrsize
             Specify the number of bytes to increment the size of ICMP payload
             after each sweep when sending sweeping pings.  The default value is

     -I iface
             Source multicast packets with the given interface address.  This
             flag only applies if the ping destination is a multicast address.

     -i wait
             Wait wait seconds between sending each packet.  The default is to
             wait for one second between each packet.  The wait time may be
             fractional, but only the super-user may specify values less than
             0.1 second.  This option is incompatible with the -f option.

     -k trafficclass
             Specifies the traffic class to use for sending ICMP packets.  The
             supported traffic classes are BK_SYS, BK, BE, RD, OAM, AV, RV, VI,
             VO and CTL.  By default ping uses the control traffic class (CTL).
             This option is an Apple addition.

     -K netservicetype
             Specifies the network service type to use for sending ICMP packets.
             The supported network service type are BK_SYS, BK, BE, RV, AV, RD,
             OAM, VI, SIG and VO.  Note this overrides the default traffic class
             (-k can still be specified after -K to use both).  This option is
             an Apple addition.

     -L      Suppress loopback of multicast packets.  This flag only applies if
             the ping destination is a multicast address.

     -l preload
             If preload is specified, ping sends that many packets as fast as
             possible before falling into its normal mode of behavior.  Only the
             super-user may use this option.

     -M mask | time
             Use ICMP_MASKREQ or ICMP_TSTAMP instead of ICMP_ECHO.  For mask,
             print the netmask of the remote machine.  Set the
             net.inet.icmp.maskrepl MIB variable to enable ICMP_MASKREPLY.  For
             time, print the origination, reception and transmission timestamps.

     -m ttl  Set the IP Time To Live for outgoing packets.  If not specified,
             the kernel uses the value of the net.inet.ip.ttl MIB variable.

     -n      Numeric output only.  No attempt will be made to lookup symbolic
             names for host addresses.

     -o      Exit successfully after receiving one reply packet.

     -P policy
             policy specifies IPsec policy for the ping session.  For details
             please refer to ipsec(4) and ipsec_set_policy(3).

     -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      Somewhat quiet output.  Don't display ICMP error messages that are
             in response to our query messages.  Originally, the -v flag was
             required to display such errors, but -v displays all ICMP error
             messages.  On a busy machine, this output can be overbearing.
             Without the -Q flag, ping prints out any ICMP error messages caused
             by its own ECHO_REQUEST messages.

     -q      Quiet output.  Nothing is displayed except the summary lines at
             startup time and when finished.

     -R      Record route.  Includes the RECORD_ROUTE option in the ECHO_REQUEST
             packet and displays the route buffer on returned packets.  This
             option is deprecated and is now a no-op.

     -r      Bypass the normal routing tables and send directly to a host on an
             attached network.  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 (e.g.,
             after the interface was dropped by routed(8)).

     -S src_addr
             Use the following IP address as the source address in outgoing
             packets.  On hosts with more than one IP address, this option can
             be used to force the source address to be something other than the
             IP address of the interface the probe packet is sent on.  If the IP
             address is not one of this machine's interface addresses, an error
             is returned and nothing is sent.

     -s packetsize
             Specify 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.  This option cannot be used with ping

     -T ttl  Set the IP Time To Live for multicasted packets.  This flag only
             applies if the ping destination is a multicast address.

     -t timeout
             Specify a timeout, in seconds, before ping exits regardless of how
             many packets have been received.

     -v      Verbose output.  ICMP packets other than ECHO_RESPONSE that are
             received are listed.

     -W waittime
             Time in milliseconds to wait for a reply for each packet sent.  If
             a reply arrives later, the packet is not printed as replied, but
             considered as replied when calculating statistics.

     -z tos  Use the specified type of service.

             Connects the socket to the destination address.  This option is an
             Apple addition.

             Prints the time a packet was received.  This option is an Apple

     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 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, mean, maximum, and standard deviation of the round-trip times.

     If ping receives a SIGINFO (see the status argument for stty(1)) signal,
     the current number of packets sent and received, and the minimum, mean, and
     maximum of the round-trip times will be written to the standard error

     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.

     An IP header without options is 20 bytes.  An ICMP ECHO_REQUEST packet
     contains an additional 8 bytes worth of ICMP header followed by an
     arbitrary amount of data.  When a packetsize is given, this indicated the
     size of this extra piece of data (the default is 56).  Thus the amount of
     data received inside of an IP packet of type ICMP ECHO_REPLY will always be
     8 bytes more than the requested data space (the ICMP header).

     If the data space is at least eight bytes large, ping uses the first eight
     bytes of this space to include a timestamp which it uses in the computation
     of round trip times.  If less than eight bytes of pad are specified, no
     round trip times are given.

     The ping utility 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 ping 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 ping.

     The TTL value of an IP packet represents the maximum number of IP routers
     that the packet can go through before being thrown away.  In current
     practice you can expect each router in the Internet to decrement the TTL
     field by exactly one.

     The TCP/IP specification recommends setting the TTL field for IP packets to
     64, but many systems use smaller values (4.3BSD uses 30, 4.2BSD used 15).

     The maximum possible value of this field is 255, and most UNIX systems set
     the TTL field of ICMP ECHO_REQUEST packets to 255.  This is why you will
     find you can “ping” some hosts, but not reach them with telnet(1) or

     In normal operation ping prints the ttl value from the packet it receives.
     When a remote system receives a ping packet, it can do one of three things
     with the TTL field in its response:

     •   Not change it; this is what BSD systems did before the 4.3BSD-Tahoe
         release.  In this case the TTL value in the received packet will be 255
         minus the number of routers in the round-trip path.

     •   Set it to 255; this is what current BSD systems do.  In this case the
         TTL value in the received packet will be 255 minus the number of
         routers in the path from the remote system to the pinging host.

     •   Set it to some other value.  Some machines use the same value for ICMP
         packets that they use for TCP packets, for example either 30 or 60.
         Others may use completely wild values.

     The ping utility exits with one of the following values:

     0       At least one response was heard from the specified host.

     2       The transmission was successful but no responses were received.

     any other value
             An error occurred.  These values are defined in <sysexits.h>.

     netstat(1), ifconfig(8), routed(8), traceroute(8), ping6(8)

     The ping utility appeared in 4.3BSD.

     The original ping utility was written by Mike Muuss while at the US Army
     Ballistics Research Laboratory.

     Flood pinging is not recommended in general, and flood pinging the
     broadcast address should only be done under very controlled conditions.

     The -v option is not worth much on busy hosts.

macOS 12.1                       March 29, 2013                       macOS 12.1