1FPING(8)                                                              FPING(8)
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3
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NAME

6       fping - send ICMP ECHO_REQUEST packets to network hosts
7

SYNOPSIS

9       fping [ options ] [ systems... ]
10

DESCRIPTION

12       fping is a program like ping which uses the Internet Control Message
13       Protocol (ICMP) echo request to determine if a target host is
14       responding.  fping differs from ping in that you can specify any number
15       of targets on the command line, or specify a file containing the lists
16       of targets to ping.  Instead of sending to one target until it times
17       out or replies, fping will send out a ping packet and move on to the
18       next target in a round-robin fashion.  In the default mode, if a target
19       replies, it is noted and removed from the list of targets to check; if
20       a target does not respond within a certain time limit and/or retry
21       limit it is designated as unreachable. fping also supports sending a
22       specified number of pings to a target, or looping indefinitely (as in
23       ping ). Unlike ping, fping is meant to be used in scripts, so its
24       output is designed to be easy to parse.  Current statistics can be
25       obtained without termination of process with signal SIGQUIT (^\ from
26       the keyboard on most systems).
27

OPTIONS

29       -4, --ipv4
30            Restrict name resolution and IPs to IPv4 addresses.
31
32       -6, --ipv6
33            Restrict name resolution and IPs to IPv6 addresses.
34
35       -a, --alive
36            Show systems that are alive.
37
38       -A, --addr
39            Display targets by address rather than DNS name. Combined with -d,
40            the output will be both the ip and (if available) the hostname.
41
42       -b, --size=BYTES
43            Number of bytes of ping data to send.  The minimum size (normally
44            12) allows room for the data that fping needs to do its work
45            (sequence number, timestamp).  The reported received data size
46            includes the IP header (normally 20 bytes) and ICMP header (8
47            bytes), so the minimum total size is 40 bytes.  Default is 56, as
48            in ping. Maximum is the theoretical maximum IP datagram size
49            (64K), though most systems limit this to a smaller, system-
50            dependent number.
51
52       -B, --backoff=N
53            Backoff factor. In the default mode, fping sends several requests
54            to a target before giving up, waiting longer for a reply on each
55            successive request.  This parameter is the value by which the wait
56            time (-t) is multiplied on each successive request; it must be
57            entered as a floating-point number (x.y). The default is 1.5.
58
59       -c, --count=N
60            Number of request packets to send to each target.  In this mode, a
61            line is displayed for each received response (this can suppressed
62            with -q or -Q).  Also, statistics about responses for each target
63            are displayed when all requests have been sent (or when
64            interrupted).
65
66       -C, --vcount=N
67            Similar to -c, but the per-target statistics are displayed in a
68            format designed for automated response-time statistics gathering.
69            For example:
70
71             $ fping -C 5 -q somehost
72             somehost : 91.7 37.0 29.2 - 36.8
73
74            shows the response time in milliseconds for each of the five
75            requests, with the "-" indicating that no response was received to
76            the fourth request.
77
78       -d, --rdns
79            Use DNS to lookup address of ping target. This allows you to give
80            fping a list of IP addresses as input and print hostnames in the
81            output. This is similar to option -n/--name, but will force a
82            reverse-DNS lookup even if you give hostnames as target
83            (NAME->IP->NAME).
84
85       -D, --timestamp
86            Add Unix timestamps in front of output lines generated with in
87            looping or counting modes (-l, -c, or -C).
88
89       -e, --elapsed
90            Show elapsed (round-trip) time of packets.
91
92       -f, --file
93            Read list of targets from a file.  This option can only be used by
94            the root user. Regular users should pipe in the file via stdin:
95
96             $ fping < targets_file
97
98       -g, --generate addr/mask
99            Generate a target list from a supplied IP netmask, or a starting
100            and ending IP.  Specify the netmask or start/end in the targets
101            portion of the command line. If a network with netmask is given,
102            the network and broadcast addresses will be excluded. ex. To ping
103            the network 192.168.1.0/24, the specified command line could look
104            like either:
105
106             $ fping -g 192.168.1.0/24
107
108            or
109
110             $ fping -g 192.168.1.1 192.168.1.254
111
112       -h, --help
113            Print usage message.
114
115       -H, --ttl=N
116            Set the IP TTL field (time to live hops).
117
118       -i, --interval=MSEC
119            The minimum amount of time (in milliseconds) between sending a
120            ping packet to any target (default is 10, minimum is 1).
121
122       -I, --iface=IFACE
123            Set the interface (requires SO_BINDTODEVICE support).
124
125       -l, --loop
126            Loop sending packets to each target indefinitely. Can be
127            interrupted with Ctrl-C; statistics about responses for each
128            target are then displayed.
129
130       -m, --all
131            Send pings to each of a target host's multiple IP addresses (use
132            of option '-A' is recommended).
133
134       -M, --dontfrag
135            Set the "Don't Fragment" bit in the IP header (used to
136            determine/test the MTU).
137
138       -n, --name
139            If targets are specified as IP addresses, do a reverse-DNS lookup
140            on them to print hostnames in the output.
141
142       -N, --netdata
143            Format output for netdata (-l -Q are required). See:
144            <http://my-netdata.io/>
145
146       -o, --outage
147            Calculate "outage time" based on the number of lost pings and the
148            interval used (useful for network convergence tests).
149
150       -O, --tos=N
151            Set the typ of service flag (TOS). N can be either decimal or
152            hexadecimal (0xh) format.
153
154       -p, --period=MSEC
155            In looping or counting modes (-l, -c, or -C), this parameter sets
156            the time in milliseconds that fping waits between successive
157            packets to an individual target. Default is 1000 and minimum is
158            10.
159
160       -q, --quiet
161            Quiet. Don't show per-probe results, but only the final summary.
162            Also don't show ICMP error messages.
163
164       -Q, --squiet=SECS
165            Like -q, but additionally show interval summary results every SECS
166            seconds.
167
168       -r, --retry=N
169            Retry limit (default 3). This is the number of times an attempt at
170            pinging a target will be made, not including the first try.
171
172       -R, --random
173            Instead of using all-zeros as the packet data, generate random
174            bytes.  Use to defeat, e.g., link data compression.
175
176       -s, --stats
177            Print cumulative statistics upon exit.
178
179       -S, --src=addr
180            Set source address.
181
182       -t, --timeout=MSEC
183            Initial target timeout in milliseconds. In the default, non-loop
184            mode, the default timeout is 500ms, and it represents the amount
185            of time that fping waits for a response to its first request.
186            Successive timeouts are multiplied by the backoff factor specified
187            with -B.
188
189            In loop/count mode, the default timeout is automatically adjusted
190            to match the "period" value (but not more than 2000ms). You can
191            still adjust the timeout value with this option, if you wish to,
192            but note that setting a value larger than "period" produces
193            inconsistent results, because the timeout value can be respected
194            only for the last ping.
195
196            Also note that any received replies that are larger than the
197            timeout value, will be discarded.
198
199       -T n Ignored (for compatibility with fping 2.4).
200
201       -u, --unreach
202            Show targets that are unreachable.
203
204       -v, --version
205            Print fping version information.
206
207       -x, --reachable=N
208            Given a list of hosts, this mode checks if number of reachable
209            hosts is >= N and exits true in that case.
210

EXAMPLES

212       Generate 20 pings to two hosts in ca. 1 second (i.e. one ping every 50
213       ms to each host), and report every ping RTT at the end:
214
215        $ fping --quiet --interval=1 --vcount=20 --period=50 127.0.0.1 127.0.0.2
216

AUTHORS

218       •   Roland J. Schemers III, Stanford University, concept and versions
219           1.x
220
221       •   RL "Bob" Morgan, Stanford University, versions 2.x
222
223       •   David Papp, versions 2.3x and up
224
225       •   David Schweikert, versions 3.0 and up
226
227       fping website: <http://www.fping.org>
228

DIAGNOSTICS

230       Exit status is 0 if all the hosts are reachable, 1 if some hosts were
231       unreachable, 2 if any IP addresses were not found, 3 for invalid
232       command line arguments, and 4 for a system call failure.
233

RESTRICTIONS

235       If fping was configured with "--enable-safe-limits", the following
236       values are not allowed for non-root users:
237
238-i n, where n < 1 msec
239
240-p n, where n < 10 msec
241

SEE ALSO

243       ping(8)
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245
246
247fping                             2022-02-06                          FPING(8)
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