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. 394