Provided by: fping_5.1-1_amd64 bug


       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


       -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 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 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

             $ 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

       -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)

       -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 10.

       -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 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, --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

       -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


       •   Roland J. Schemers III, Stanford University, concept and versions 1.x

       •   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