xref: /freebsd/sbin/ping/ping.8 (revision ee2bf73496dc0e978e40fc12781b84fbd30e9282)
18fae3551SRodney W. Grimes.\" Copyright (c) 1985, 1991, 1993
28fae3551SRodney W. Grimes.\"	The Regents of the University of California.  All rights reserved.
38fae3551SRodney W. Grimes.\"
48fae3551SRodney W. Grimes.\" Redistribution and use in source and binary forms, with or without
58fae3551SRodney W. Grimes.\" modification, are permitted provided that the following conditions
68fae3551SRodney W. Grimes.\" are met:
78fae3551SRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright
88fae3551SRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer.
98fae3551SRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright
108fae3551SRodney W. Grimes.\"    notice, this list of conditions and the following disclaimer in the
118fae3551SRodney W. Grimes.\"    documentation and/or other materials provided with the distribution.
128fae3551SRodney W. Grimes.\" 3. All advertising materials mentioning features or use of this software
138fae3551SRodney W. Grimes.\"    must display the following acknowledgement:
148fae3551SRodney W. Grimes.\"	This product includes software developed by the University of
158fae3551SRodney W. Grimes.\"	California, Berkeley and its contributors.
168fae3551SRodney W. Grimes.\" 4. Neither the name of the University nor the names of its contributors
178fae3551SRodney W. Grimes.\"    may be used to endorse or promote products derived from this software
188fae3551SRodney W. Grimes.\"    without specific prior written permission.
198fae3551SRodney W. Grimes.\"
208fae3551SRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
218fae3551SRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
228fae3551SRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
238fae3551SRodney W. Grimes.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
248fae3551SRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
258fae3551SRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
268fae3551SRodney W. Grimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
278fae3551SRodney W. Grimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
288fae3551SRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
298fae3551SRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
308fae3551SRodney W. Grimes.\" SUCH DAMAGE.
318fae3551SRodney W. Grimes.\"
328fae3551SRodney W. Grimes.\"     @(#)ping.8	8.2 (Berkeley) 12/11/93
33ee2bf734SWarner Losh.\"	$Id: ping.8,v 1.9 1997/03/02 06:32:42 imp Exp $
348fae3551SRodney W. Grimes.\"
3543470e3bSGarrett Wollman.Dd March 1, 1997
368fae3551SRodney W. Grimes.Dt PING 8
378fae3551SRodney W. Grimes.Os BSD 4.3
388fae3551SRodney W. Grimes.Sh NAME
398fae3551SRodney W. Grimes.Nm ping
408fae3551SRodney W. Grimes.Nd send
418fae3551SRodney W. Grimes.Tn ICMP ECHO_REQUEST
428fae3551SRodney W. Grimespackets to network hosts
438fae3551SRodney W. Grimes.Sh SYNOPSIS
448fae3551SRodney W. Grimes.Nm ping
45f78ac61bSWarner Losh.Op Fl QRadfnqrv
468fae3551SRodney W. Grimes.Op Fl c Ar count
478fae3551SRodney W. Grimes.Op Fl i Ar wait
488fae3551SRodney W. Grimes.Op Fl l Ar preload
498fae3551SRodney W. Grimes.Op Fl p Ar pattern
508fae3551SRodney W. Grimes.Op Fl s Ar packetsize
51f78ac61bSWarner Losh[
5285456935SBill Fenner.Ar host
53f78ac61bSWarner Losh|
54f78ac61bSWarner Losh.Op Fl L
55f78ac61bSWarner Losh.Op Fl I Ar interface
56f78ac61bSWarner Losh.Op Fl T Ar ttl
57f78ac61bSWarner Losh.Ar mcast-group
58f78ac61bSWarner Losh]
598fae3551SRodney W. Grimes.Sh DESCRIPTION
608fae3551SRodney W. Grimes.Nm Ping
618fae3551SRodney W. Grimesuses the
628fae3551SRodney W. Grimes.Tn ICMP
638fae3551SRodney W. Grimesprotocol's mandatory
648fae3551SRodney W. Grimes.Tn ECHO_REQUEST
658fae3551SRodney W. Grimesdatagram to elicit an
668fae3551SRodney W. Grimes.Tn ICMP ECHO_RESPONSE
678fae3551SRodney W. Grimesfrom a host or gateway.
688fae3551SRodney W. Grimes.Tn ECHO_REQUEST
698fae3551SRodney W. Grimesdatagrams (``pings'') have an IP and
708fae3551SRodney W. Grimes.Tn ICMP
718fae3551SRodney W. Grimesheader,
728fae3551SRodney W. Grimesfollowed by a
738fae3551SRodney W. Grimes.Dq struct timeval
748fae3551SRodney W. Grimesand then an arbitrary number of ``pad'' bytes used to fill out the
758fae3551SRodney W. Grimespacket.
768fae3551SRodney W. GrimesThe options are as follows:
778fae3551SRodney W. Grimes.Bl -tag -width Ds
78772dfa72SDaniel O'Callaghan.It Fl a
79772dfa72SDaniel O'CallaghanAudible. Include a bell (ASCII 0x07) character in the output when any packet
80772dfa72SDaniel O'Callaghanis received. This option is ignored if other format options are present.
818fae3551SRodney W. Grimes.It Fl c Ar count
828fae3551SRodney W. GrimesStop after sending (and receiving)
838fae3551SRodney W. Grimes.Ar count
848fae3551SRodney W. Grimes.Tn ECHO_RESPONSE
858fae3551SRodney W. Grimespackets.
868fae3551SRodney W. Grimes.It Fl d
878fae3551SRodney W. GrimesSet the
888fae3551SRodney W. Grimes.Dv SO_DEBUG
898fae3551SRodney W. Grimesoption on the socket being used.
908fae3551SRodney W. Grimes.It Fl f
918fae3551SRodney W. GrimesFlood ping.
928fae3551SRodney W. GrimesOutputs packets as fast as they come back or one hundred times per second,
938fae3551SRodney W. Grimeswhichever is more.
948fae3551SRodney W. GrimesFor every
958fae3551SRodney W. Grimes.Tn ECHO_REQUEST
968fae3551SRodney W. Grimessent a period ``.'' is printed, while for every
978fae3551SRodney W. Grimes.Tn ECHO_REPLY
988fae3551SRodney W. Grimesreceived a backspace is printed.
998fae3551SRodney W. GrimesThis provides a rapid display of how many packets are being dropped.
1008fae3551SRodney W. GrimesOnly the super-user may use this option.
1018fae3551SRodney W. Grimes.Bf -emphasis
1028fae3551SRodney W. GrimesThis can be very hard on a network and should be used with caution.
1038fae3551SRodney W. Grimes.Ef
1048fae3551SRodney W. Grimes.It Fl i Ar wait
1058fae3551SRodney W. GrimesWait
1068fae3551SRodney W. Grimes.Ar wait
1078fae3551SRodney W. Grimesseconds
1088fae3551SRodney W. Grimes.Em between sending each packet .
1098fae3551SRodney W. GrimesThe default is to wait for one second between each packet.
1108fae3551SRodney W. GrimesThis option is incompatible with the
1118fae3551SRodney W. Grimes.Fl f
1128fae3551SRodney W. Grimesoption.
11385456935SBill Fenner.It Fl I Ar interface
11485456935SBill FennerSource multicast packets with the given interface address.
11585456935SBill FennerThis flag only applies if the ping destination is a multicast address.
1168fae3551SRodney W. Grimes.It Fl l Ar preload
1178fae3551SRodney W. GrimesIf
1188fae3551SRodney W. Grimes.Ar preload
1198fae3551SRodney W. Grimesis specified,
1208fae3551SRodney W. Grimes.Nm ping
1218fae3551SRodney W. Grimessends that many packets as fast as possible before falling into its normal
1228fae3551SRodney W. Grimesmode of behavior.
123ee2bf734SWarner LoshOnly the super-user may use this option.
12485456935SBill Fenner.It Fl L
12585456935SBill FennerSuppress loopback of multicast packets.
12685456935SBill FennerThis flag only applies if the ping destination is a multicast address.
1278fae3551SRodney W. Grimes.It Fl n
1288fae3551SRodney W. GrimesNumeric output only.
1298fae3551SRodney W. GrimesNo attempt will be made to lookup symbolic names for host addresses.
1308fae3551SRodney W. Grimes.It Fl p Ar pattern
1318fae3551SRodney W. GrimesYou may specify up to 16 ``pad'' bytes to fill out the packet you send.
1328fae3551SRodney W. GrimesThis is useful for diagnosing data-dependent problems in a network.
1338fae3551SRodney W. GrimesFor example,
1348fae3551SRodney W. Grimes.Dq Li \-p ff
1358fae3551SRodney W. Grimeswill cause the sent packet to be filled with all
1368fae3551SRodney W. Grimesones.
137ef9e6dc7SBill Fenner.It Fl Q
138ef9e6dc7SBill FennerSomewhat quiet output.
139ef9e6dc7SBill FennerDon't display ICMP error messages that are in response to our query messages.
140ef9e6dc7SBill FennerOriginally, the
141ef9e6dc7SBill Fenner.Fl v
142ef9e6dc7SBill Fennerflag was required to display such errors, but
143ef9e6dc7SBill Fenner.Fl v
144ef9e6dc7SBill Fennerdisplays all ICMP error messages.  On a busy machine, this output can
145ef9e6dc7SBill Fennerbe overbearing.  Without the
146ef9e6dc7SBill Fenner.Fl Q
147ef9e6dc7SBill Fennerflag,
148ef9e6dc7SBill Fenner.Nm
149ef9e6dc7SBill Fennerprints out any ICMP error messages caused by its own ECHO_REQUEST
150ef9e6dc7SBill Fennermessages.
1518fae3551SRodney W. Grimes.It Fl q
1528fae3551SRodney W. GrimesQuiet output.
1538fae3551SRodney W. GrimesNothing is displayed except the summary lines at startup time and
1548fae3551SRodney W. Grimeswhen finished.
1558fae3551SRodney W. Grimes.It Fl R
1568fae3551SRodney W. GrimesRecord route.
1578fae3551SRodney W. GrimesIncludes the
1588fae3551SRodney W. Grimes.Tn RECORD_ROUTE
1598fae3551SRodney W. Grimesoption in the
1608fae3551SRodney W. Grimes.Tn ECHO_REQUEST
1618fae3551SRodney W. Grimespacket and displays
1628fae3551SRodney W. Grimesthe route buffer on returned packets.
16343470e3bSGarrett WollmanNote that the IP header is only large enough for nine such routes;
16443470e3bSGarrett Wollmanthe
16543470e3bSGarrett Wollman.Xr traceroute 8
16643470e3bSGarrett Wollmancommand is usually better at determining the route packets take to a
16743470e3bSGarrett Wollmanparticular destination.
16843470e3bSGarrett WollmanMany hosts ignore or discard the
16943470e3bSGarrett Wollman.Tn RECORD_ROUTE
17043470e3bSGarrett Wollmanoption.
1718fae3551SRodney W. Grimes.It Fl r
1728fae3551SRodney W. GrimesBypass the normal routing tables and send directly to a host on an attached
1738fae3551SRodney W. Grimesnetwork.
1748fae3551SRodney W. GrimesIf the host is not on a directly-attached network, an error is returned.
1758fae3551SRodney W. GrimesThis option can be used to ping a local host through an interface
1768fae3551SRodney W. Grimesthat has no route through it (e.g., after the interface was dropped by
1778fae3551SRodney W. Grimes.Xr routed 8 ) .
1788fae3551SRodney W. Grimes.It Fl s Ar packetsize
1798fae3551SRodney W. GrimesSpecifies the number of data bytes to be sent.
1808fae3551SRodney W. GrimesThe default is 56, which translates into 64
1818fae3551SRodney W. Grimes.Tn ICMP
1828fae3551SRodney W. Grimesdata bytes when combined
1838fae3551SRodney W. Grimeswith the 8 bytes of
1848fae3551SRodney W. Grimes.Tn ICMP
1858fae3551SRodney W. Grimesheader data.
18685456935SBill Fenner.It Fl T Ar ttl
18785456935SBill FennerSet the IP Time To Live for multicasted packets.
18885456935SBill FennerThis flag only applies if the ping destination is a multicast address.
1898fae3551SRodney W. Grimes.It Fl v
1908fae3551SRodney W. GrimesVerbose output.
1918fae3551SRodney W. Grimes.Tn ICMP
1928fae3551SRodney W. Grimespackets other than
1938fae3551SRodney W. Grimes.Tn ECHO_RESPONSE
1948fae3551SRodney W. Grimesthat are received are listed.
1958fae3551SRodney W. Grimes.El
1968fae3551SRodney W. Grimes.Pp
1978fae3551SRodney W. GrimesWhen using
1988fae3551SRodney W. Grimes.Nm ping
1998fae3551SRodney W. Grimesfor fault isolation, it should first be run on the local host, to verify
2008fae3551SRodney W. Grimesthat the local network interface is up and running.
2018fae3551SRodney W. GrimesThen, hosts and gateways further and further away should be ``pinged''.
2028fae3551SRodney W. GrimesRound-trip times and packet loss statistics are computed.
2038fae3551SRodney W. GrimesIf duplicate packets are received, they are not included in the packet
2048fae3551SRodney W. Grimesloss calculation, although the round trip time of these packets is used
2058fae3551SRodney W. Grimesin calculating the minimum/average/maximum round-trip time numbers.
2068fae3551SRodney W. GrimesWhen the specified number of packets have been sent (and received) or
2078fae3551SRodney W. Grimesif the program is terminated with a
2088fae3551SRodney W. Grimes.Dv SIGINT ,
2098fae3551SRodney W. Grimesa brief summary is displayed.
2108fae3551SRodney W. Grimes.Pp
2118fae3551SRodney W. GrimesThis program is intended for use in network testing, measurement and
2128fae3551SRodney W. Grimesmanagement.
2138fae3551SRodney W. GrimesBecause of the load it can impose on the network, it is unwise to use
2148fae3551SRodney W. Grimes.Nm ping
2158fae3551SRodney W. Grimesduring normal operations or from automated scripts.
2168fae3551SRodney W. Grimes.Sh ICMP PACKET DETAILS
2178fae3551SRodney W. GrimesAn IP header without options is 20 bytes.
2188fae3551SRodney W. GrimesAn
2198fae3551SRodney W. Grimes.Tn ICMP
2208fae3551SRodney W. Grimes.Tn ECHO_REQUEST
2218fae3551SRodney W. Grimespacket contains an additional 8 bytes worth
2228fae3551SRodney W. Grimesof
2238fae3551SRodney W. Grimes.Tn ICMP
2248fae3551SRodney W. Grimesheader followed by an arbitrary amount of data.
2258fae3551SRodney W. GrimesWhen a
2268fae3551SRodney W. Grimes.Ar packetsize
2278fae3551SRodney W. Grimesis given, this indicated the size of this extra piece of data (the
2288fae3551SRodney W. Grimesdefault is 56).
2298fae3551SRodney W. GrimesThus the amount of data received inside of an IP packet of type
2308fae3551SRodney W. Grimes.Tn ICMP
2318fae3551SRodney W. Grimes.Tn ECHO_REPLY
2328fae3551SRodney W. Grimeswill always be 8 bytes more than the requested data space
2338fae3551SRodney W. Grimes(the
2348fae3551SRodney W. Grimes.Tn ICMP
2358fae3551SRodney W. Grimesheader).
2368fae3551SRodney W. Grimes.Pp
2378fae3551SRodney W. GrimesIf the data space is at least eight bytes large,
2388fae3551SRodney W. Grimes.Nm ping
2398fae3551SRodney W. Grimesuses the first eight bytes of this space to include a timestamp which
2408fae3551SRodney W. Grimesit uses in the computation of round trip times.
2418fae3551SRodney W. GrimesIf less than eight bytes of pad are specified, no round trip times are
2428fae3551SRodney W. Grimesgiven.
2438fae3551SRodney W. Grimes.Sh DUPLICATE AND DAMAGED PACKETS
2448fae3551SRodney W. Grimes.Nm Ping
2458fae3551SRodney W. Grimeswill report duplicate and damaged packets.
24685456935SBill FennerDuplicate packets should never occur when pinging a unicast address,
24785456935SBill Fennerand seem to be caused by
2488fae3551SRodney W. Grimesinappropriate link-level retransmissions.
2498fae3551SRodney W. GrimesDuplicates may occur in many situations and are rarely (if ever) a
2508fae3551SRodney W. Grimesgood sign, although the presence of low levels of duplicates may not
2518fae3551SRodney W. Grimesalways be cause for alarm.
25285456935SBill FennerDuplicates are expected when pinging a broadcast or multicast address,
25385456935SBill Fennersince they are not really duplicates but replies from different hosts
25485456935SBill Fennerto the same request.
2558fae3551SRodney W. Grimes.Pp
2568fae3551SRodney W. GrimesDamaged packets are obviously serious cause for alarm and often
2578fae3551SRodney W. Grimesindicate broken hardware somewhere in the
2588fae3551SRodney W. Grimes.Nm ping
2598fae3551SRodney W. Grimespacket's path (in the network or in the hosts).
2608fae3551SRodney W. Grimes.Sh TRYING DIFFERENT DATA PATTERNS
2618fae3551SRodney W. GrimesThe (inter)network layer should never treat packets differently depending
2628fae3551SRodney W. Grimeson the data contained in the data portion.
2638fae3551SRodney W. GrimesUnfortunately, data-dependent problems have been known to sneak into
2648fae3551SRodney W. Grimesnetworks and remain undetected for long periods of time.
2658fae3551SRodney W. GrimesIn many cases the particular pattern that will have problems is something
2668fae3551SRodney W. Grimesthat doesn't have sufficient ``transitions'', such as all ones or all
2678fae3551SRodney W. Grimeszeros, or a pattern right at the edge, such as almost all zeros.
2688fae3551SRodney W. GrimesIt isn't necessarily enough to specify a data pattern of all zeros (for
2698fae3551SRodney W. Grimesexample) on the command line because the pattern that is of interest is
2708fae3551SRodney W. Grimesat the data link level, and the relationship between what you type and
2718fae3551SRodney W. Grimeswhat the controllers transmit can be complicated.
2728fae3551SRodney W. Grimes.Pp
2738fae3551SRodney W. GrimesThis means that if you have a data-dependent problem you will probably
2748fae3551SRodney W. Grimeshave to do a lot of testing to find it.
2758fae3551SRodney W. GrimesIf you are lucky, you may manage to find a file that either can't be sent
2768fae3551SRodney W. Grimesacross your network or that takes much longer to transfer than other
2778fae3551SRodney W. Grimessimilar length files.
2788fae3551SRodney W. GrimesYou can then examine this file for repeated patterns that you can test
2798fae3551SRodney W. Grimesusing the
2808fae3551SRodney W. Grimes.Fl p
2818fae3551SRodney W. Grimesoption of
2828fae3551SRodney W. Grimes.Nm ping .
2838fae3551SRodney W. Grimes.Sh TTL DETAILS
2848fae3551SRodney W. GrimesThe
2858fae3551SRodney W. Grimes.Tn TTL
2868fae3551SRodney W. Grimesvalue of an IP packet represents the maximum number of IP routers
2878fae3551SRodney W. Grimesthat the packet can go through before being thrown away.
2888fae3551SRodney W. GrimesIn current practice you can expect each router in the Internet to decrement
2898fae3551SRodney W. Grimesthe
2908fae3551SRodney W. Grimes.Tn TTL
2918fae3551SRodney W. Grimesfield by exactly one.
2928fae3551SRodney W. Grimes.Pp
2938fae3551SRodney W. GrimesThe
2948fae3551SRodney W. Grimes.Tn TCP/IP
2958fae3551SRodney W. Grimesspecification states that the
2968fae3551SRodney W. Grimes.Tn TTL
2978fae3551SRodney W. Grimesfield for
2988fae3551SRodney W. Grimes.Tn TCP
2998fae3551SRodney W. Grimespackets should
3008fae3551SRodney W. Grimesbe set to 60, but many systems use smaller values (4.3
3018fae3551SRodney W. Grimes.Tn BSD
3028fae3551SRodney W. Grimesuses 30, 4.2 used
3038fae3551SRodney W. Grimes15).
3048fae3551SRodney W. Grimes.Pp
3058fae3551SRodney W. GrimesThe maximum possible value of this field is 255, and most Unix systems set
3068fae3551SRodney W. Grimesthe
3078fae3551SRodney W. Grimes.Tn TTL
3088fae3551SRodney W. Grimesfield of
3098fae3551SRodney W. Grimes.Tn ICMP ECHO_REQUEST
3108fae3551SRodney W. Grimespackets to 255.
3118fae3551SRodney W. GrimesThis is why you will find you can ``ping'' some hosts, but not reach them
3128fae3551SRodney W. Grimeswith
3138fae3551SRodney W. Grimes.Xr telnet 1
3148fae3551SRodney W. Grimesor
3158fae3551SRodney W. Grimes.Xr ftp 1 .
3168fae3551SRodney W. Grimes.Pp
3178fae3551SRodney W. GrimesIn normal operation ping prints the ttl value from the packet it receives.
3188fae3551SRodney W. GrimesWhen a remote system receives a ping packet, it can do one of three things
3198fae3551SRodney W. Grimeswith the
3208fae3551SRodney W. Grimes.Tn TTL
3218fae3551SRodney W. Grimesfield in its response:
3228fae3551SRodney W. Grimes.Bl -bullet
3238fae3551SRodney W. Grimes.It
3248fae3551SRodney W. GrimesNot change it; this is what Berkeley Unix systems did before the
3258fae3551SRodney W. Grimes.Bx 4.3 tahoe
3268fae3551SRodney W. Grimesrelease.
3278fae3551SRodney W. GrimesIn this case the
3288fae3551SRodney W. Grimes.Tn TTL
3298fae3551SRodney W. Grimesvalue in the received packet will be 255 minus the
3308fae3551SRodney W. Grimesnumber of routers in the round-trip path.
3318fae3551SRodney W. Grimes.It
3328fae3551SRodney W. GrimesSet it to 255; this is what current Berkeley Unix systems do.
3338fae3551SRodney W. GrimesIn this case the
3348fae3551SRodney W. Grimes.Tn TTL
3358fae3551SRodney W. Grimesvalue in the received packet will be 255 minus the
3368fae3551SRodney W. Grimesnumber of routers in the path
3378fae3551SRodney W. Grimes.Xr from
3388fae3551SRodney W. Grimesthe remote system
3398fae3551SRodney W. Grimes.Em to
3408fae3551SRodney W. Grimesthe
3418fae3551SRodney W. Grimes.Nm ping Ns Em ing
3428fae3551SRodney W. Grimeshost.
3438fae3551SRodney W. Grimes.It
3448fae3551SRodney W. GrimesSet it to some other value.
3458fae3551SRodney W. GrimesSome machines use the same value for
3468fae3551SRodney W. Grimes.Tn ICMP
3478fae3551SRodney W. Grimespackets that they use for
3488fae3551SRodney W. Grimes.Tn TCP
3498fae3551SRodney W. Grimespackets, for example either 30 or 60.
3508fae3551SRodney W. GrimesOthers may use completely wild values.
3518fae3551SRodney W. Grimes.El
35243470e3bSGarrett Wollman.Sh RETURN VALUES
35343470e3bSGarrett WollmanThe
35443470e3bSGarrett Wollman.Nm ping
35543470e3bSGarrett Wollmancommand returns an exit status of zero if at least one response was
35643470e3bSGarrett Wollmanheard from the specified
35743470e3bSGarrett Wollman.Ar host ;
35843470e3bSGarrett Wollmana status of two if the transmission was successful but no responses
35943470e3bSGarrett Wollmanwere received; or another value
36043470e3bSGarrett Wollman.Pq from Aq Pa sysexits.h
36143470e3bSGarrett Wollmanif an error occurred.
36243470e3bSGarrett Wollman.Sh SEE ALSO
36343470e3bSGarrett Wollman.Xr netstat 1 ,
36443470e3bSGarrett Wollman.Xr ifconfig 8 ,
36543470e3bSGarrett Wollman.Xr routed 8 ,
36643470e3bSGarrett Wollman.Xr traceroute 8
36743470e3bSGarrett Wollman.Sh HISTORY
36843470e3bSGarrett WollmanThe
36943470e3bSGarrett Wollman.Nm
37043470e3bSGarrett Wollmancommand appeared in
37143470e3bSGarrett Wollman.Bx 4.3 .
37243470e3bSGarrett Wollman.Sh AUTHORS
37343470e3bSGarrett WollmanThe original
37443470e3bSGarrett Wollman.Nm
37543470e3bSGarrett Wollmancommand was written by Mike Muuss while at the US Army Ballistics
37643470e3bSGarrett WollmanResearch Laboratory.
3778fae3551SRodney W. Grimes.Sh BUGS
3788fae3551SRodney W. GrimesMany Hosts and Gateways ignore the
3798fae3551SRodney W. Grimes.Tn RECORD_ROUTE
3808fae3551SRodney W. Grimesoption.
3818fae3551SRodney W. Grimes.Pp
3828fae3551SRodney W. GrimesThe maximum IP header length is too small for options like
3838fae3551SRodney W. Grimes.Tn RECORD_ROUTE
3848fae3551SRodney W. Grimesto
3858fae3551SRodney W. Grimesbe completely useful.
386e83201b4SWolfram SchneiderThere's not much that can be done about this, however.
3878fae3551SRodney W. Grimes.Pp
3888fae3551SRodney W. GrimesFlood pinging is not recommended in general, and flood pinging the
3898fae3551SRodney W. Grimesbroadcast address should only be done under very controlled conditions.
390ef9e6dc7SBill Fenner.Pp
391ef9e6dc7SBill FennerThe
392ef9e6dc7SBill Fenner.Fl v
393ef9e6dc7SBill Fenneroption is not worth much on busy hosts.
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