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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 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 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

       -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 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, --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: <>

       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


fping				  2020-08-05			      FPING(8)


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