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man pages section 8: System Administration Commands

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Updated: Wednesday, July 27, 2022

fping (8)


fping - send ICMP ECHO_REQUEST packets to network hosts


fping [ options ] [ systems... ]


FPING(8)                                                              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.  Current statistics can be
       obtained without termination of process with signal SIGQUIT (^\ from
       the keyboard on most systems).

       -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 hostname.

       -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 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

       -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 ping target. 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 stdin:

             $ 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:

             $ 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 print hostnames in the output.

       -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
            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 additionally show interval summary results every SECS

       -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, --stats
            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.

       -x, --reachable=N
            Given a list of hosts, this mode checks if number of reachable
            hosts is >= N and exits true in that case.

       Generate 20 pings to two hosts in ca. 1 second (i.e. one ping every 50
       ms to each host), and report every ping RTT at the end:

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

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

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

       o   David Papp, versions 2.3x and up

       o   David Schweikert, versions 3.0 and up

       fping website: <http://www.fping.org>

       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:

       o   -i n, where n < 1 msec

       o   -p n, where n < 10 msec

       See attributes(7) for descriptions of the following attributes:

       |Availability   | diagnostic/fping |
       |Stability      | Volatile         |


       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from  http://www.fping.org/dist/fping-5.1.tar.gz.

       Further information about this software can be found on the open source
       community website at http://www.fping.org/.

fping                             2022-02-06                          FPING(8)