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                                    - 1 -      Formatted:  February 22, 2019

 FPING(8)                           fping                           FPING(8)

      fping - send ICMP ECHO_REQUEST packets to network hosts

      fping [ options ] [ systems... ]

      fping is a program like ping which uses the Internet Control Message
      Protocol (ICMP) echo request to determine if a target host is
      responding.  fping differs from ping in that you can specify any
      number of targets on the command line, or specify a file containing
      the lists of targets to ping.  Instead of sending to one target until
      it times out or replies, fping will send out a ping packet and move on
      to the next target in a round-robin fashion.  In the default mode, if
      a target replies, it is noted and removed from the list of targets to
      check; if a target does not respond within a certain time limit and/or
      retry limit it is designated as unreachable. fping also supports
      sending a specified number of pings to a target, or looping
      indefinitely (as in ping ). Unlike ping, fping is meant to be used in
      scripts, so its output is designed to be easy to parse.

      -4, --ipv4
           Restrict name resolution and IPs to IPv4 addresses.

      -6, --ipv6
           Restrict name resolution and IPs to IPv6 addresses.

      -a, --alive
           Show systems that are alive.

      -A, --addr
           Display targets by address rather than DNS name. Combined with
           -d, the output will be both the ip and (if available) the

      -b, --size=BYTES
           Number of bytes of ping data to send.  The minimum size (normally
           12) allows room for the data that fping needs to do its work
           (sequence number, timestamp).  The reported received data size
           includes the IP header (normally 20 bytes) and ICMP header (8
           bytes), so the minimum total size is 40 bytes.  Default is 56, as
           in ping. Maximum is the theoretical maximum IP datagram size
           (64K), though most systems limit this to a smaller, system-
           dependent number.

      -B, --backoff=N
           Backoff factor. In the default mode, fping sends several requests
           to a target before giving up, waiting longer for a reply on each
           successive request.  This parameter is the value by which the
           wait time (-t) is multiplied on each successive request; it must

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 FPING(8)                           fping                           FPING(8)

           be entered as a floating-point number (x.y). The default is 1.5.

      -c, --count=N
           Number of request packets to send to each target.  In this mode,
           a line is displayed for each received response (this can
           suppressed with -q or -Q).  Also, statistics about responses for
           each target are displayed when all requests have been sent (or
           when interrupted).

      -C, --vcount=N
           Similar to -c, but the per-target statistics are displayed in a
           format designed for automated response-time statistics gathering.
           For example:

            $ fping -C 5 -q somehost
            somehost : 91.7 37.0 29.2 - 36.8

           shows the response time in milliseconds for each of the five
           requests, with the "-" indicating that no response was received
           to the fourth request.

      -d, --rdns
           Use DNS to lookup address of return ping packet. This allows you
           to give fping a list of IP addresses as input and print hostnames
           in the output. This is similar to option -n/--name, but will
           force a reverse-DNS lookup even if you give hostnames as target

      -D, --timestamp
           Add Unix timestamps in front of output lines generated with in
           looping or counting modes (-l, -c, or -C).

      -e, --elapsed
           Show elapsed (round-trip) time of packets.

      -f, --file
           Read list of targets from a file.  This option can only be used
           by the root user. Regular users should pipe in the file via

            $ fping < targets_file

      -g, --generate addr/mask
           Generate a target list from a supplied IP netmask, or a starting
           and ending IP.  Specify the netmask or start/end in the targets
           portion of the command line. If a network with netmask is given,
           the network and broadcast addresses will be excluded. ex. To ping
           the network, the specified command line could look
           like either:

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 FPING(8)                           fping                           FPING(8)

            $ fping -g


            $ fping -g

      -h, --help
           Print usage message.

      -H, --ttl=N
           Set the IP TTL field (time to live hops).

      -i, --interval=MSEC
           The minimum amount of time (in milliseconds) between sending a
           ping packet to any target (default is 10, minimum is 1).

      -I, --iface=IFACE
           Set the interface (requires SO_BINDTODEVICE support).

      -l, --loop
           Loop sending packets to each target indefinitely. Can be
           interrupted with Ctrl-C; statistics about responses for each
           target are then displayed.

      -m, --all
           Send pings to each of a target host's multiple IP addresses (use
           of option '-A' is recommended).

      -M, --dontfrag
           Set the "Don't Fragment" bit in the IP header (used to
           determine/test the MTU).

      -n, --name
           If targets are specified as IP addresses, do a reverse-DNS lookup
           on them to

      -N, --netdata
           Format output for netdata (-l -Q are required). See:

      -o, --outage
           Calculate "outage time" based on the number of lost pings and the
           interval used (useful for network convergence tests).

      -O, --tos=N
           Set the typ of service flag (TOS). N can be either decimal or
           hexadecimal (0xh) format.

      -p, --period=MSEC
           In looping or counting modes (-l, -c, or -C), this parameter sets
           the time in milliseconds that fping waits between successive

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 FPING(8)                           fping                           FPING(8)

           packets to an individual target. Default is 1000 and minimum is

      -q, --quiet
           Quiet. Don't show per-probe results, but only the final summary.
           Also don't show ICMP error messages.

      -Q, --squiet=SECS
           Like -q, but show summary results every n seconds.

      -r, --retry=N
           Retry limit (default 3). This is the number of times an attempt
           at pinging a target will be made, not including the first try.

      -R, --random
           Instead of using all-zeros as the packet data, generate random
           bytes.  Use to defeat, e.g., link data compression.

      -s, --src
           Print cumulative statistics upon exit.

      -S, --src=addr
           Set source address.

      -t, --timeout=MSEC
           Initial target timeout in milliseconds. In the default, non-loop
           mode, the default timeout is 500ms, and it represents the amount
           of time that fping waits for a response to its first request.
           Successive timeouts are multiplied by the backoff factor
           specified with -B.

           In loop/count mode, the default timeout is automatically adjusted
           to match the "period" value (but not more than 2000ms). You can
           still adjust the timeout value with this option, if you wish to,
           but note that setting a value larger than "period" produces
           inconsistent results, because the timeout value can be respected
           only for the last ping.

           Also note that any received replies that are larger than the
           timeout value, will be discarded.

      -T n Ignored (for compatibility with fping 2.4).

      -u, --unreach
           Show targets that are unreachable.

      -v, --version
           Print fping version information.

      Generate 20 pings to two hosts in ca. 1 second (i.e. one ping every 50

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 FPING(8)                           fping                           FPING(8)

      ms to each host), and report every ping RTT at the end:

       $ fping --quiet --interval=1 --vcount=20 --period=50

      +   Roland J. Schemers III, Stanford University, concept and versions

      +   RL "Bob" Morgan, Stanford University, versions 2.x

      +   David Papp, versions 2.3x and up

      +   David Schweikert, versions 3.0 and up

      fping website: <>

      Exit status is 0 if all the hosts are reachable, 1 if some hosts were
      unreachable, 2 if any IP addresses were not found, 3 for invalid
      command line arguments, and 4 for a system call failure.

      If fping was configured with "--enable-safe-limits", the following
      values are not allowed for non-root users:

      +   -i n, where n < 1 msec

      +   -p n, where n < 10 msec


                                    - 5 -      Formatted:  February 22, 2019