1FPING(8) FPING(8)
2
6 fping - send ICMP ECHO_REQUEST packets to network hosts
7
9 fping [ options ] [ systems... ]
10
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.
25
27 -4, --ipv4
28 Restrict name resolution and IPs to IPv4 addresses.
29 -6, --ipv6
31 Restrict name resolution and IPs to IPv6 addresses.
32 -a, --alive
34 Show systems that are alive.
35 -A, --addr
37 Display targets by address rather than DNS name. Combined with -d,
38 the output will be both the ip and (if available) the hostname.
39 -b, --size=BYTES
41 Number of bytes of ping data to send. The minimum size (normally
42 12) allows room for the data that fping needs to do its work
43 (sequence number, timestamp). The reported received data size
44 includes the IP header (normally 20 bytes) and ICMP header (8
45 bytes), so the minimum total size is 40 bytes. Default is 56, as
46 in ping. Maximum is the theoretical maximum IP datagram size
47 (64K), though most systems limit this to a smaller, system-
48 dependent number.
49 -B, --backoff=N
51 Backoff factor. In the default mode, fping sends several requests
52 to a target before giving up, waiting longer for a reply on each
53 successive request. This parameter is the value by which the wait
54 time (-t) is multiplied on each successive request; it must be
55 entered as a floating-point number (x.y). The default is 1.5.
56 -c, --count=N
58 Number of request packets to send to each target. In this mode, a
59 line is displayed for each received response (this can suppressed
60 with -q or -Q). Also, statistics about responses for each target
61 are displayed when all requests have been sent (or when
62 interrupted).
63 -C, --vcount=N
65 Similar to -c, but the per-target statistics are displayed in a
66 format designed for automated response-time statistics gathering.
67 For example:
68 $ fping -C 5 -q somehost
70 somehost : 91.7 37.0 29.2 - 36.8
71 shows the response time in milliseconds for each of the five
73 requests, with the "-" indicating that no response was received to
74 the fourth request.
75 -d, --rdns
77 Use DNS to lookup address of return ping packet. This allows you
78 to give fping a list of IP addresses as input and print hostnames
79 in the output. This is similar to option -n/--name, but will force
80 a reverse-DNS lookup even if you give hostnames as target
81 (NAME->IP->NAME).
82 -D, --timestamp
84 Add Unix timestamps in front of output lines generated with in
85 looping or counting modes (-l, -c, or -C).
86 -e, --elapsed
88 Show elapsed (round-trip) time of packets.
89 -f, --file
91 Read list of targets from a file. This option can only be used by
92 the root user. Regular users should pipe in the file via stdin:
93 $ fping < targets_file
95 -g, --generate addr/mask
97 Generate a target list from a supplied IP netmask, or a starting
98 and ending IP. Specify the netmask or start/end in the targets
99 portion of the command line. If a network with netmask is given,
100 the network and broadcast addresses will be excluded. ex. To ping
101 the network 192.168.1.0/24, the specified command line could look
102 like either:
103 $ fping -g 192.168.1.0/24
105 or
107 $ fping -g 192.168.1.1 192.168.1.254
109 -h, --help
111 Print usage message.
112 -H, --ttl=N
114 Set the IP TTL field (time to live hops).
115 -i, --interval=MSEC
117 The minimum amount of time (in milliseconds) between sending a
118 ping packet to any target (default is 10, minimum is 1).
119 -I, --iface=IFACE
121 Set the interface (requires SO_BINDTODEVICE support).
122 -l, --loop
124 Loop sending packets to each target indefinitely. Can be
125 interrupted with Ctrl-C; statistics about responses for each
126 target are then displayed.
127 -m, --all
129 Send pings to each of a target host's multiple IP addresses (use
130 of option '-A' is recommended).
131 -M, --dontfrag
133 Set the "Don't Fragment" bit in the IP header (used to
134 determine/test the MTU).
135 -n, --name
137 If targets are specified as IP addresses, do a reverse-DNS lookup
138 on them to
139 -N, --netdata
141 Format output for netdata (-l -Q are required). See:
142 <http://my-netdata.io/>
143 -o, --outage
145 Calculate "outage time" based on the number of lost pings and the
146 interval used (useful for network convergence tests).
147 -O, --tos=N
149 Set the typ of service flag (TOS). N can be either decimal or
150 hexadecimal (0xh) format.
151 -p, --period=MSEC
153 In looping or counting modes (-l, -c, or -C), this parameter sets
154 the time in milliseconds that fping waits between successive
155 packets to an individual target. Default is 1000 and minimum is
156 10.
157 -q, --quiet
159 Quiet. Don't show per-probe results, but only the final summary.
160 Also don't show ICMP error messages.
161 -Q, --squiet=SECS
163 Like -q, but show summary results every n seconds.
164 -r, --retry=N
166 Retry limit (default 3). This is the number of times an attempt at
167 pinging a target will be made, not including the first try.
168 -R, --random
170 Instead of using all-zeros as the packet data, generate random
171 bytes. Use to defeat, e.g., link data compression.
172 -s, --src
174 Print cumulative statistics upon exit.
175 -S, --src=addr
177 Set source address.
178 -t, --timeout=MSEC
180 Initial target timeout in milliseconds. In the default, non-loop
181 mode, the default timeout is 500ms, and it represents the amount
182 of time that fping waits for a response to its first request.
183 Successive timeouts are multiplied by the backoff factor specified
184 with -B.
185 In loop/count mode, the default timeout is automatically adjusted
187 to match the "period" value (but not more than 2000ms). You can
188 still adjust the timeout value with this option, if you wish to,
189 but note that setting a value larger than "period" produces
190 inconsistent results, because the timeout value can be respected
191 only for the last ping.
192 Also note that any received replies that are larger than the
194 timeout value, will be discarded.
195 -T n Ignored (for compatibility with fping 2.4).
197 -u, --unreach
199 Show targets that are unreachable.
200 -v, --version
202 Print fping version information.
203 -x, --reachable=N
205 Given a list of hosts, this mode checks if number of reachable
206 hosts is >= N and exits true in that case.
207
209 Generate 20 pings to two hosts in ca. 1 second (i.e. one ping every 50
210 ms to each host), and report every ping RTT at the end:
211 $ fping --quiet --interval=1 --vcount=20 --period=50 127.0.0.1 127.0.0.2
213
215 · Roland J. Schemers III, Stanford University, concept and versions
216 1.x
217 · RL "Bob" Morgan, Stanford University, versions 2.x
219 · David Papp, versions 2.3x and up
221 · David Schweikert, versions 3.0 and up
223 fping website: <http://www.fping.org>
225
227 Exit status is 0 if all the hosts are reachable, 1 if some hosts were
228 unreachable, 2 if any IP addresses were not found, 3 for invalid
229 command line arguments, and 4 for a system call failure.
230
232 If fping was configured with "--enable-safe-limits", the following
233 values are not allowed for non-root users:
234 · -i n, where n < 1 msec
236 · -p n, where n < 10 msec
238
240 ping(8)
241fping 2019-02-19 FPING(8)