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.\" 4. Neither the name of the University nor the names of its contributors 138fae3551SRodney W. Grimes.\" may be used to endorse or promote products derived from this software 148fae3551SRodney W. Grimes.\" without specific prior written permission. 158fae3551SRodney W. Grimes.\" 168fae3551SRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 178fae3551SRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 188fae3551SRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 198fae3551SRodney W. Grimes.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 208fae3551SRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 218fae3551SRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 228fae3551SRodney W. Grimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 238fae3551SRodney W. Grimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 248fae3551SRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 258fae3551SRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 268fae3551SRodney W. Grimes.\" SUCH DAMAGE. 278fae3551SRodney W. Grimes.\" 288fae3551SRodney W. Grimes.\" @(#)ping.8 8.2 (Berkeley) 12/11/93 297f3dea24SPeter Wemm.\" $FreeBSD$ 308fae3551SRodney W. Grimes.\" 319ff95228SGleb Smirnoff.Dd August 15, 2005 328fae3551SRodney W. Grimes.Dt PING 8 339fe48c6eSRuslan Ermilov.Os 348fae3551SRodney W. Grimes.Sh NAME 358fae3551SRodney W. Grimes.Nm ping 368fae3551SRodney W. Grimes.Nd send 378fae3551SRodney W. Grimes.Tn ICMP ECHO_REQUEST 388fae3551SRodney W. Grimespackets to network hosts 398fae3551SRodney W. Grimes.Sh SYNOPSIS 407c7fb079SRuslan Ermilov.Nm 412c56e246SMatthew N. Dodd.Op Fl AaDdfnoQqRrv 428fae3551SRodney W. Grimes.Op Fl c Ar count 439ff95228SGleb Smirnoff.Op Fl G Ar sweepmaxsize 449ff95228SGleb Smirnoff.Op Fl g Ar sweepminsize 459ff95228SGleb Smirnoff.Op Fl h Ar sweepincrsize 468fae3551SRodney W. Grimes.Op Fl i Ar wait 478fae3551SRodney W. Grimes.Op Fl l Ar preload 481bd10ba2SRuslan Ermilov.Op Fl M Cm mask | time 49211bfbd2SRuslan Ermilov.Op Fl m Ar ttl 509a4365d0SYoshinobu Inoue.Op Fl P Ar policy 511f6a4631SRuslan Ermilov.Op Fl p Ar pattern 5299490edeSWarner Losh.Op Fl S Ar src_addr 531f6a4631SRuslan Ermilov.Op Fl s Ar packetsize 54bf113f1bSBill Fumerola.Op Fl t Ar timeout 550b2f8b3fSMaxim Konovalov.Op Fl z Ar tos 561bd10ba2SRuslan Ermilov.Ar host 571bd10ba2SRuslan Ermilov.Nm 582c56e246SMatthew N. Dodd.Op Fl AaDdfLnoQqRrv 591bd10ba2SRuslan Ermilov.Op Fl c Ar count 601bd10ba2SRuslan Ermilov.Op Fl I Ar iface 611bd10ba2SRuslan Ermilov.Op Fl i Ar wait 621bd10ba2SRuslan Ermilov.Op Fl l Ar preload 631bd10ba2SRuslan Ermilov.Op Fl M Cm mask | time 641bd10ba2SRuslan Ermilov.Op Fl m Ar ttl 651bd10ba2SRuslan Ermilov.Op Fl P Ar policy 661bd10ba2SRuslan Ermilov.Op Fl p Ar pattern 671bd10ba2SRuslan Ermilov.Op Fl S Ar src_addr 681bd10ba2SRuslan Ermilov.Op Fl s Ar packetsize 69f78ac61bSWarner Losh.Op Fl T Ar ttl 701bd10ba2SRuslan Ermilov.Op Fl t Ar timeout 711bd10ba2SRuslan Ermilov.Op Fl z Ar tos 72f78ac61bSWarner Losh.Ar mcast-group 738fae3551SRodney W. Grimes.Sh DESCRIPTION 74e1205e80SPhilippe CharnierThe 75e1205e80SPhilippe Charnier.Nm 76e1205e80SPhilippe Charnierutility uses the 778fae3551SRodney W. Grimes.Tn ICMP 7850ceac88SJohn-Mark Gurney.No protocol Ap s mandatory 798fae3551SRodney W. Grimes.Tn ECHO_REQUEST 808fae3551SRodney W. Grimesdatagram to elicit an 818fae3551SRodney W. Grimes.Tn ICMP ECHO_RESPONSE 828fae3551SRodney W. Grimesfrom a host or gateway. 838fae3551SRodney W. Grimes.Tn ECHO_REQUEST 8450ceac88SJohn-Mark Gurneydatagrams 8550ceac88SJohn-Mark Gurney.Pq Dq pings 8650ceac88SJohn-Mark Gurneyhave an IP and 878fae3551SRodney W. Grimes.Tn ICMP 8850ceac88SJohn-Mark Gurneyheader, followed by a 898fae3551SRodney W. Grimes.Dq struct timeval 9050ceac88SJohn-Mark Gurneyand then an arbitrary number of 9150ceac88SJohn-Mark Gurney.Dq pad 921f6a4631SRuslan Ermilovbytes used to fill out the packet. 931f6a4631SRuslan ErmilovThe options are as follows: 94e345a80dSPhilippe Charnier.Bl -tag -width indent 95ca517ad8SPoul-Henning Kamp.It Fl A 96ca517ad8SPoul-Henning KampAudible. 9725107197SIan DowseOutput a bell 98c4d9468eSRuslan Ermilov.Tn ( ASCII 99c4d9468eSRuslan Ermilov0x07) 10025107197SIan Dowsecharacter when no packet is received before the next packet 101ca517ad8SPoul-Henning Kampis transmitted. 10225107197SIan DowseTo cater for round-trip times that are longer than the interval 10325107197SIan Dowsebetween transmissions, further missing packets cause a bell only 10425107197SIan Dowseif the maximum number of unreceived packets has increased. 105772dfa72SDaniel O'Callaghan.It Fl a 106ef8f7ac9SSheldon HearnAudible. 107ef8f7ac9SSheldon HearnInclude a bell 108c4d9468eSRuslan Ermilov.Tn ( ASCII 109c4d9468eSRuslan Ermilov0x07) 110ef8f7ac9SSheldon Hearncharacter in the output when any packet is received. 111ef8f7ac9SSheldon HearnThis option is ignored 11250ceac88SJohn-Mark Gurneyif other format options are present. 1138fae3551SRodney W. Grimes.It Fl c Ar count 11450ceac88SJohn-Mark GurneyStop after sending 115c4d9468eSRuslan Ermilov(and receiving) 1168fae3551SRodney W. Grimes.Ar count 1178fae3551SRodney W. Grimes.Tn ECHO_RESPONSE 1180ed77db8SBruce Evanspackets. 1190ed77db8SBruce EvansIf this option is not specified, 1200ed77db8SBruce Evans.Nm 1210ed77db8SBruce Evanswill operate until interrupted. 1229ff95228SGleb SmirnoffIf this option is specified in conjunction with ping sweeps, 1239ff95228SGleb Smirnoffeach sweep will consist of 1249ff95228SGleb Smirnoff.Ar count 1259ff95228SGleb Smirnoffpackets. 1261f6a4631SRuslan Ermilov.It Fl D 1271f6a4631SRuslan ErmilovSet the Don't Fragment bit. 1288fae3551SRodney W. Grimes.It Fl d 1298fae3551SRodney W. GrimesSet the 1308fae3551SRodney W. Grimes.Dv SO_DEBUG 1318fae3551SRodney W. Grimesoption on the socket being used. 1328fae3551SRodney W. Grimes.It Fl f 1338fae3551SRodney W. GrimesFlood ping. 1348fae3551SRodney W. GrimesOutputs packets as fast as they come back or one hundred times per second, 1358fae3551SRodney W. Grimeswhichever is more. 1368fae3551SRodney W. GrimesFor every 1378fae3551SRodney W. Grimes.Tn ECHO_REQUEST 13850ceac88SJohn-Mark Gurneysent a period 1391252c1bbSRuslan Ermilov.Dq .\& 14050ceac88SJohn-Mark Gurneyis printed, while for every 1418fae3551SRodney W. Grimes.Tn ECHO_REPLY 1420ed77db8SBruce Evansreceived a backspace is printed. 1438fae3551SRodney W. GrimesThis provides a rapid display of how many packets are being dropped. 1448fae3551SRodney W. GrimesOnly the super-user may use this option. 1458fae3551SRodney W. Grimes.Bf -emphasis 1468fae3551SRodney W. GrimesThis can be very hard on a network and should be used with caution. 1478fae3551SRodney W. Grimes.Ef 1489ff95228SGleb Smirnoff.It Fl G Ar sweepmaxsize 1499ff95228SGleb SmirnoffSpecify the maximum size of 1509ff95228SGleb Smirnoff.Tn ICMP 1519ff95228SGleb Smirnoffpayload when sending sweeping pings. 1529ff95228SGleb SmirnoffThis option is required for ping sweeps. 1539ff95228SGleb Smirnoff.It Fl g Ar sweepminsize 1549ff95228SGleb SmirnoffSpecify the size of 1559ff95228SGleb Smirnoff.Tn ICMP 1569ff95228SGleb Smirnoffpayload to start with when sending sweeping pings. 1579ff95228SGleb SmirnoffThe default value is 0. 1589ff95228SGleb Smirnoff.It Fl h Ar sweepincrsize 1599ff95228SGleb SmirnoffSpecify the number of bytes to increment the size of 1609ff95228SGleb Smirnoff.Tn ICMP 1619ff95228SGleb Smirnoffpayload after 1629ff95228SGleb Smirnoffeach sweep when sending sweeping pings. The default value is 1. 1631bd10ba2SRuslan Ermilov.It Fl I Ar iface 1641f6a4631SRuslan ErmilovSource multicast packets with the given interface address. 1651f6a4631SRuslan ErmilovThis flag only applies if the ping destination is a multicast address. 1668fae3551SRodney W. Grimes.It Fl i Ar wait 1678fae3551SRodney W. GrimesWait 1688fae3551SRodney W. Grimes.Ar wait 1698fae3551SRodney W. Grimesseconds 1708fae3551SRodney W. Grimes.Em between sending each packet . 1710ed77db8SBruce EvansThe default is to wait for one second between each packet. 1720ed77db8SBruce EvansThe wait time may be fractional, but only the super-user may specify 173074ad115SRuslan Ermilovvalues less than 1 second. 1740ed77db8SBruce EvansThis option is incompatible with the 1758fae3551SRodney W. Grimes.Fl f 1768fae3551SRodney W. Grimesoption. 1771f6a4631SRuslan Ermilov.It Fl L 1781f6a4631SRuslan ErmilovSuppress loopback of multicast packets. 17985456935SBill FennerThis flag only applies if the ping destination is a multicast address. 1808fae3551SRodney W. Grimes.It Fl l Ar preload 1818fae3551SRodney W. GrimesIf 1828fae3551SRodney W. Grimes.Ar preload 1838fae3551SRodney W. Grimesis specified, 184e345a80dSPhilippe Charnier.Nm 1858fae3551SRodney W. Grimessends that many packets as fast as possible before falling into its normal 1868fae3551SRodney W. Grimesmode of behavior. 187ee2bf734SWarner LoshOnly the super-user may use this option. 1881bd10ba2SRuslan Ermilov.It Fl M Cm mask | time 1891bd10ba2SRuslan ErmilovUse 1901bd10ba2SRuslan Ermilov.Dv ICMP_MASKREQ 1911bd10ba2SRuslan Ermilovor 1921bd10ba2SRuslan Ermilov.Dv ICMP_TSTAMP 1931bd10ba2SRuslan Ermilovinstead of 1941bd10ba2SRuslan Ermilov.Dv ICMP_ECHO . 195eb1543c6SMatthew N. DoddFor 1961bd10ba2SRuslan Ermilov.Cm mask , 1971bd10ba2SRuslan Ermilovprint the netmask of the remote machine. 1981bd10ba2SRuslan ErmilovSet the 1991bd10ba2SRuslan Ermilov.Va net.inet.icmp.maskrepl 2001bd10ba2SRuslan ErmilovMIB variable to enable 2011bd10ba2SRuslan Ermilov.Dv ICMP_MASKREPLY . 2021bd10ba2SRuslan ErmilovFor 2031bd10ba2SRuslan Ermilov.Cm time , 2041fb474d8SMatthew N. Doddprint the origination, reception and transmission timestamps. 2059b085129SMatthew N. Dodd.It Fl m Ar ttl 2069b085129SMatthew N. DoddSet the IP Time To Live for outgoing packets. 2079b085129SMatthew N. DoddIf not specified, the kernel uses the value of the 2089b085129SMatthew N. Dodd.Va net.inet.ip.ttl 2099b085129SMatthew N. DoddMIB variable. 2108fae3551SRodney W. Grimes.It Fl n 2118fae3551SRodney W. GrimesNumeric output only. 2128fae3551SRodney W. GrimesNo attempt will be made to lookup symbolic names for host addresses. 2138025c44bSDima Dorfman.It Fl o 2148025c44bSDima DorfmanExit successfully after receiving one reply packet. 2151f6a4631SRuslan Ermilov.It Fl P Ar policy 2161f6a4631SRuslan Ermilov.Ar policy 2171f6a4631SRuslan Ermilovspecifies IPsec policy for the ping session. 2181f6a4631SRuslan ErmilovFor details please refer to 2191f6a4631SRuslan Ermilov.Xr ipsec 4 2201f6a4631SRuslan Ermilovand 2211f6a4631SRuslan Ermilov.Xr ipsec_set_policy 3 . 2228fae3551SRodney W. Grimes.It Fl p Ar pattern 22350ceac88SJohn-Mark GurneyYou may specify up to 16 22450ceac88SJohn-Mark Gurney.Dq pad 22550ceac88SJohn-Mark Gurneybytes to fill out the packet you send. 2268fae3551SRodney W. GrimesThis is useful for diagnosing data-dependent problems in a network. 2278fae3551SRodney W. GrimesFor example, 2288fae3551SRodney W. Grimes.Dq Li \-p ff 2298fae3551SRodney W. Grimeswill cause the sent packet to be filled with all 2308fae3551SRodney W. Grimesones. 231ef9e6dc7SBill Fenner.It Fl Q 232ef9e6dc7SBill FennerSomewhat quiet output. 23350ceac88SJohn-Mark Gurney.No Don Ap t 23450ceac88SJohn-Mark Gurneydisplay ICMP error messages that are in response to our query messages. 235ef9e6dc7SBill FennerOriginally, the 236ef9e6dc7SBill Fenner.Fl v 237ef9e6dc7SBill Fennerflag was required to display such errors, but 238ef9e6dc7SBill Fenner.Fl v 2391f6a4631SRuslan Ermilovdisplays all ICMP error messages. 2401f6a4631SRuslan ErmilovOn a busy machine, this output can be overbearing. 2411f6a4631SRuslan ErmilovWithout the 242ef9e6dc7SBill Fenner.Fl Q 243ef9e6dc7SBill Fennerflag, 244ef9e6dc7SBill Fenner.Nm 245ef9e6dc7SBill Fennerprints out any ICMP error messages caused by its own ECHO_REQUEST 246ef9e6dc7SBill Fennermessages. 2478fae3551SRodney W. Grimes.It Fl q 2488fae3551SRodney W. GrimesQuiet output. 2498fae3551SRodney W. GrimesNothing is displayed except the summary lines at startup time and 2508fae3551SRodney W. Grimeswhen finished. 2518fae3551SRodney W. Grimes.It Fl R 2528fae3551SRodney W. GrimesRecord route. 2538fae3551SRodney W. GrimesIncludes the 2548fae3551SRodney W. Grimes.Tn RECORD_ROUTE 2558fae3551SRodney W. Grimesoption in the 2568fae3551SRodney W. Grimes.Tn ECHO_REQUEST 2578fae3551SRodney W. Grimespacket and displays 2588fae3551SRodney W. Grimesthe route buffer on returned packets. 25943470e3bSGarrett WollmanNote that the IP header is only large enough for nine such routes; 26043470e3bSGarrett Wollmanthe 26143470e3bSGarrett Wollman.Xr traceroute 8 26243470e3bSGarrett Wollmancommand is usually better at determining the route packets take to a 26343470e3bSGarrett Wollmanparticular destination. 264c03e877aSWarner LoshIf more routes come back than should, such as due to an illegal spoofed 265c03e877aSWarner Loshpacket, ping will print the route list and then truncate it at the correct 266c03e877aSWarner Loshspot. 26743470e3bSGarrett WollmanMany hosts ignore or discard the 26843470e3bSGarrett Wollman.Tn RECORD_ROUTE 26943470e3bSGarrett Wollmanoption. 2708fae3551SRodney W. Grimes.It Fl r 2718fae3551SRodney W. GrimesBypass the normal routing tables and send directly to a host on an attached 2728fae3551SRodney W. Grimesnetwork. 2738fae3551SRodney W. GrimesIf the host is not on a directly-attached network, an error is returned. 2748fae3551SRodney W. GrimesThis option can be used to ping a local host through an interface 27550ceac88SJohn-Mark Gurneythat has no route through it 276c4d9468eSRuslan Ermilov(e.g., after the interface was dropped by 277c4d9468eSRuslan Ermilov.Xr routed 8 ) . 2781f6a4631SRuslan Ermilov.It Fl S Ar src_addr 2791f6a4631SRuslan ErmilovUse the following IP address as the source address in outgoing packets. 2801f6a4631SRuslan ErmilovOn hosts with more than one IP address, this option can be used to 2811f6a4631SRuslan Ermilovforce the source address to be something other than the IP address 2821f6a4631SRuslan Ermilovof the interface the probe packet is sent on. 2831f6a4631SRuslan ErmilovIf the IP address 2841f6a4631SRuslan Ermilovis not one of this machine's interface addresses, an error is 2851f6a4631SRuslan Ermilovreturned and nothing is sent. 2868fae3551SRodney W. Grimes.It Fl s Ar packetsize 287e345a80dSPhilippe CharnierSpecify the number of data bytes to be sent. 2888fae3551SRodney W. GrimesThe default is 56, which translates into 64 2898fae3551SRodney W. Grimes.Tn ICMP 2908fae3551SRodney W. Grimesdata bytes when combined 2918fae3551SRodney W. Grimeswith the 8 bytes of 2928fae3551SRodney W. Grimes.Tn ICMP 2930ed77db8SBruce Evansheader data. 294fb7d32c7SMaxim KonovalovOnly the super-user may specify values more than default. 2959ff95228SGleb SmirnoffThis option cannot be used with ping sweeps. 29685456935SBill Fenner.It Fl T Ar ttl 29785456935SBill FennerSet the IP Time To Live for multicasted packets. 29885456935SBill FennerThis flag only applies if the ping destination is a multicast address. 2991f6a4631SRuslan Ermilov.It Fl t Ar timeout 3001f6a4631SRuslan ErmilovSpecify a timeout, in seconds, before ping exits regardless of how 3011f6a4631SRuslan Ermilovmany packets have been received. 3028fae3551SRodney W. Grimes.It Fl v 3038fae3551SRodney W. GrimesVerbose output. 3048fae3551SRodney W. Grimes.Tn ICMP 3058fae3551SRodney W. Grimespackets other than 3068fae3551SRodney W. Grimes.Tn ECHO_RESPONSE 3078fae3551SRodney W. Grimesthat are received are listed. 3080b2f8b3fSMaxim Konovalov.It Fl z Ar tos 3090b2f8b3fSMaxim KonovalovUse the specified type of service. 3108fae3551SRodney W. Grimes.El 3118fae3551SRodney W. Grimes.Pp 3128fae3551SRodney W. GrimesWhen using 31350ceac88SJohn-Mark Gurney.Nm 3148fae3551SRodney W. Grimesfor fault isolation, it should first be run on the local host, to verify 3158fae3551SRodney W. Grimesthat the local network interface is up and running. 31650ceac88SJohn-Mark GurneyThen, hosts and gateways further and further away should be 31750ceac88SJohn-Mark Gurney.Dq pinged . 3188fae3551SRodney W. GrimesRound-trip times and packet loss statistics are computed. 3198fae3551SRodney W. GrimesIf duplicate packets are received, they are not included in the packet 3208fae3551SRodney W. Grimesloss calculation, although the round trip time of these packets is used 3213109a910SGarrett Wollmanin calculating the round-trip time statistics. 32250ceac88SJohn-Mark GurneyWhen the specified number of packets have been sent 323c4d9468eSRuslan Ermilov(and received) 32450ceac88SJohn-Mark Gurneyor if the program is terminated with a 3258fae3551SRodney W. Grimes.Dv SIGINT , 3263109a910SGarrett Wollmana brief summary is displayed, showing the number of packets sent and 327605af08dSMaxim Konovalovreceived, and the minimum, mean, maximum, and standard deviation of 3283109a910SGarrett Wollmanthe round-trip times. 3298fae3551SRodney W. Grimes.Pp 330605af08dSMaxim KonovalovIf 331605af08dSMaxim Konovalov.Nm 332605af08dSMaxim Konovalovreceives a 333605af08dSMaxim Konovalov.Dv SIGINFO 334605af08dSMaxim Konovalov(see the 335605af08dSMaxim Konovalov.Cm status 336605af08dSMaxim Konovalovargument for 337605af08dSMaxim Konovalov.Xr stty 1 ) 338605af08dSMaxim Konovalovsignal, the current number of packets sent and received, and the 339605af08dSMaxim Konovalovminimum, mean, and maximum of the round-trip times will be written to 340605af08dSMaxim Konovalovthe standard error output. 341605af08dSMaxim Konovalov.Pp 3428fae3551SRodney W. GrimesThis program is intended for use in network testing, measurement and 3438fae3551SRodney W. Grimesmanagement. 3448fae3551SRodney W. GrimesBecause of the load it can impose on the network, it is unwise to use 34550ceac88SJohn-Mark Gurney.Nm 3468fae3551SRodney W. Grimesduring normal operations or from automated scripts. 3478fae3551SRodney W. Grimes.Sh ICMP PACKET DETAILS 3488fae3551SRodney W. GrimesAn IP header without options is 20 bytes. 3498fae3551SRodney W. GrimesAn 3508fae3551SRodney W. Grimes.Tn ICMP 3518fae3551SRodney W. Grimes.Tn ECHO_REQUEST 35250ceac88SJohn-Mark Gurneypacket contains an additional 8 bytes worth of 3538fae3551SRodney W. Grimes.Tn ICMP 3548fae3551SRodney W. Grimesheader followed by an arbitrary amount of data. 3558fae3551SRodney W. GrimesWhen a 3568fae3551SRodney W. Grimes.Ar packetsize 35750ceac88SJohn-Mark Gurneyis given, this indicated the size of this extra piece of data 358c4d9468eSRuslan Ermilov(the default is 56). 3598fae3551SRodney W. GrimesThus the amount of data received inside of an IP packet of type 3608fae3551SRodney W. Grimes.Tn ICMP 3618fae3551SRodney W. Grimes.Tn ECHO_REPLY 3628fae3551SRodney W. Grimeswill always be 8 bytes more than the requested data space 363c4d9468eSRuslan Ermilov(the 364c4d9468eSRuslan Ermilov.Tn ICMP 365c4d9468eSRuslan Ermilovheader). 3668fae3551SRodney W. Grimes.Pp 3678fae3551SRodney W. GrimesIf the data space is at least eight bytes large, 36850ceac88SJohn-Mark Gurney.Nm 3698fae3551SRodney W. Grimesuses the first eight bytes of this space to include a timestamp which 3708fae3551SRodney W. Grimesit uses in the computation of round trip times. 3718fae3551SRodney W. GrimesIf less than eight bytes of pad are specified, no round trip times are 3728fae3551SRodney W. Grimesgiven. 3738fae3551SRodney W. Grimes.Sh DUPLICATE AND DAMAGED PACKETS 374e1205e80SPhilippe CharnierThe 375e1205e80SPhilippe Charnier.Nm 376e1205e80SPhilippe Charnierutility will report duplicate and damaged packets. 37785456935SBill FennerDuplicate packets should never occur when pinging a unicast address, 37885456935SBill Fennerand seem to be caused by 3798fae3551SRodney W. Grimesinappropriate link-level retransmissions. 38050ceac88SJohn-Mark GurneyDuplicates may occur in many situations and are rarely 381c4d9468eSRuslan Ermilov(if ever) 38250ceac88SJohn-Mark Gurneya good sign, although the presence of low levels of duplicates may not 3838fae3551SRodney W. Grimesalways be cause for alarm. 38485456935SBill FennerDuplicates are expected when pinging a broadcast or multicast address, 38585456935SBill Fennersince they are not really duplicates but replies from different hosts 38685456935SBill Fennerto the same request. 3878fae3551SRodney W. Grimes.Pp 3888fae3551SRodney W. GrimesDamaged packets are obviously serious cause for alarm and often 3898fae3551SRodney W. Grimesindicate broken hardware somewhere in the 390e345a80dSPhilippe Charnier.Nm 3913109a910SGarrett Wollmanpacket's path (in the network or in the hosts). 3928fae3551SRodney W. Grimes.Sh TRYING DIFFERENT DATA PATTERNS 39350ceac88SJohn-Mark GurneyThe 3943109a910SGarrett Wollman(inter)network 39550ceac88SJohn-Mark Gurneylayer should never treat packets differently depending on the data 39650ceac88SJohn-Mark Gurneycontained in the data portion. 3978fae3551SRodney W. GrimesUnfortunately, data-dependent problems have been known to sneak into 3988fae3551SRodney W. Grimesnetworks and remain undetected for long periods of time. 3998fae3551SRodney W. GrimesIn many cases the particular pattern that will have problems is something 4003109a910SGarrett Wollmanthat does not have sufficient 40150ceac88SJohn-Mark Gurney.Dq transitions , 40250ceac88SJohn-Mark Gurneysuch as all ones or all zeros, or a pattern right at the edge, such as 40350ceac88SJohn-Mark Gurneyalmost all zeros. 4043109a910SGarrett WollmanIt is not 4053109a910SGarrett Wollmannecessarily enough to specify a data pattern of all zeros (for example) 40650ceac88SJohn-Mark Gurneyon the command line because the pattern that is of interest is 4078fae3551SRodney W. Grimesat the data link level, and the relationship between what you type and 4088fae3551SRodney W. Grimeswhat the controllers transmit can be complicated. 4098fae3551SRodney W. Grimes.Pp 4108fae3551SRodney W. GrimesThis means that if you have a data-dependent problem you will probably 4118fae3551SRodney W. Grimeshave to do a lot of testing to find it. 41250ceac88SJohn-Mark GurneyIf you are lucky, you may manage to find a file that either 4133109a910SGarrett Wollmancannot 41450ceac88SJohn-Mark Gurneybe sent across your network or that takes much longer to transfer than 41550ceac88SJohn-Mark Gurneyother similar length files. 4168fae3551SRodney W. GrimesYou can then examine this file for repeated patterns that you can test 4178fae3551SRodney W. Grimesusing the 4188fae3551SRodney W. Grimes.Fl p 4198fae3551SRodney W. Grimesoption of 4207c7fb079SRuslan Ermilov.Nm . 4218fae3551SRodney W. Grimes.Sh TTL DETAILS 4228fae3551SRodney W. GrimesThe 4238fae3551SRodney W. Grimes.Tn TTL 4248fae3551SRodney W. Grimesvalue of an IP packet represents the maximum number of IP routers 4258fae3551SRodney W. Grimesthat the packet can go through before being thrown away. 4268fae3551SRodney W. GrimesIn current practice you can expect each router in the Internet to decrement 4278fae3551SRodney W. Grimesthe 4288fae3551SRodney W. Grimes.Tn TTL 4298fae3551SRodney W. Grimesfield by exactly one. 4308fae3551SRodney W. Grimes.Pp 4318fae3551SRodney W. GrimesThe 4328fae3551SRodney W. Grimes.Tn TCP/IP 433a70dc556SRuslan Ermilovspecification recommends setting the 4348fae3551SRodney W. Grimes.Tn TTL 4358fae3551SRodney W. Grimesfield for 436a70dc556SRuslan Ermilov.Tn IP 437a70dc556SRuslan Ermilovpackets to 64, but many systems use smaller values 438c4d9468eSRuslan Ermilov.No ( Bx 4.3 4393109a910SGarrett Wollmanuses 30, 4403109a910SGarrett Wollman.Bx 4.2 441c4d9468eSRuslan Ermilovused 15). 4428fae3551SRodney W. Grimes.Pp 443e345a80dSPhilippe CharnierThe maximum possible value of this field is 255, and most 444e345a80dSPhilippe Charnier.Ux 445e345a80dSPhilippe Charniersystems set 4468fae3551SRodney W. Grimesthe 4478fae3551SRodney W. Grimes.Tn TTL 4488fae3551SRodney W. Grimesfield of 4498fae3551SRodney W. Grimes.Tn ICMP ECHO_REQUEST 4508fae3551SRodney W. Grimespackets to 255. 45150ceac88SJohn-Mark GurneyThis is why you will find you can 45250ceac88SJohn-Mark Gurney.Dq ping 45350ceac88SJohn-Mark Gurneysome hosts, but not reach them with 4548fae3551SRodney W. Grimes.Xr telnet 1 4558fae3551SRodney W. Grimesor 4568fae3551SRodney W. Grimes.Xr ftp 1 . 4578fae3551SRodney W. Grimes.Pp 458e345a80dSPhilippe CharnierIn normal operation 459e345a80dSPhilippe Charnier.Nm 460e345a80dSPhilippe Charnierprints the ttl value from the packet it receives. 4618fae3551SRodney W. GrimesWhen a remote system receives a ping packet, it can do one of three things 4628fae3551SRodney W. Grimeswith the 4638fae3551SRodney W. Grimes.Tn TTL 4648fae3551SRodney W. Grimesfield in its response: 4658fae3551SRodney W. Grimes.Bl -bullet 4668fae3551SRodney W. Grimes.It 467e345a80dSPhilippe CharnierNot change it; this is what 468e345a80dSPhilippe Charnier.Bx 469e345a80dSPhilippe Charniersystems did before the 4708fae3551SRodney W. Grimes.Bx 4.3 tahoe 4718fae3551SRodney W. Grimesrelease. 4728fae3551SRodney W. GrimesIn this case the 4738fae3551SRodney W. Grimes.Tn TTL 4748fae3551SRodney W. Grimesvalue in the received packet will be 255 minus the 4758fae3551SRodney W. Grimesnumber of routers in the round-trip path. 4768fae3551SRodney W. Grimes.It 4773109a910SGarrett WollmanSet it to 255; this is what current 478e345a80dSPhilippe Charnier.Bx 4793109a910SGarrett Wollmansystems do. 4808fae3551SRodney W. GrimesIn this case the 4818fae3551SRodney W. Grimes.Tn TTL 4828fae3551SRodney W. Grimesvalue in the received packet will be 255 minus the 4838fae3551SRodney W. Grimesnumber of routers in the path 48450ceac88SJohn-Mark Gurney.Em from 4858fae3551SRodney W. Grimesthe remote system 4868fae3551SRodney W. Grimes.Em to 4878fae3551SRodney W. Grimesthe 48850ceac88SJohn-Mark Gurney.Nm Ns Em ing 4898fae3551SRodney W. Grimeshost. 4908fae3551SRodney W. Grimes.It 4918fae3551SRodney W. GrimesSet it to some other value. 4928fae3551SRodney W. GrimesSome machines use the same value for 4938fae3551SRodney W. Grimes.Tn ICMP 4948fae3551SRodney W. Grimespackets that they use for 4958fae3551SRodney W. Grimes.Tn TCP 4968fae3551SRodney W. Grimespackets, for example either 30 or 60. 4978fae3551SRodney W. GrimesOthers may use completely wild values. 4988fae3551SRodney W. Grimes.El 49943470e3bSGarrett Wollman.Sh RETURN VALUES 50043470e3bSGarrett WollmanThe 50150ceac88SJohn-Mark Gurney.Nm 502e1205e80SPhilippe Charnierutility returns an exit status of zero if at least one response was 50343470e3bSGarrett Wollmanheard from the specified 50443470e3bSGarrett Wollman.Ar host ; 50543470e3bSGarrett Wollmana status of two if the transmission was successful but no responses 50643470e3bSGarrett Wollmanwere received; or another value 507c4d9468eSRuslan Ermilov(from 508fe08efe6SRuslan Ermilov.In sysexits.h ) 50943470e3bSGarrett Wollmanif an error occurred. 51043470e3bSGarrett Wollman.Sh SEE ALSO 51143470e3bSGarrett Wollman.Xr netstat 1 , 51243470e3bSGarrett Wollman.Xr ifconfig 8 , 51343470e3bSGarrett Wollman.Xr routed 8 , 51443470e3bSGarrett Wollman.Xr traceroute 8 51543470e3bSGarrett Wollman.Sh HISTORY 51643470e3bSGarrett WollmanThe 51743470e3bSGarrett Wollman.Nm 518e1205e80SPhilippe Charnierutility appeared in 51943470e3bSGarrett Wollman.Bx 4.3 . 52043470e3bSGarrett Wollman.Sh AUTHORS 52143470e3bSGarrett WollmanThe original 52243470e3bSGarrett Wollman.Nm 523e1205e80SPhilippe Charnierutility was written by 52468085a0eSPhilippe Charnier.An Mike Muuss 52568085a0eSPhilippe Charnierwhile at the US Army Ballistics 52643470e3bSGarrett WollmanResearch Laboratory. 5278fae3551SRodney W. Grimes.Sh BUGS 5288fae3551SRodney W. GrimesMany Hosts and Gateways ignore the 5298fae3551SRodney W. Grimes.Tn RECORD_ROUTE 5308fae3551SRodney W. Grimesoption. 5318fae3551SRodney W. Grimes.Pp 5328fae3551SRodney W. GrimesThe maximum IP header length is too small for options like 5338fae3551SRodney W. Grimes.Tn RECORD_ROUTE 53450ceac88SJohn-Mark Gurneyto be completely useful. 53550ceac88SJohn-Mark Gurney.No There Ap s 53650ceac88SJohn-Mark Gurneynot much that can be done about this, however. 5378fae3551SRodney W. Grimes.Pp 5388fae3551SRodney W. GrimesFlood pinging is not recommended in general, and flood pinging the 5398fae3551SRodney W. Grimesbroadcast address should only be done under very controlled conditions. 540ef9e6dc7SBill Fenner.Pp 541ef9e6dc7SBill FennerThe 542ef9e6dc7SBill Fenner.Fl v 543ef9e6dc7SBill Fenneroption is not worth much on busy hosts. 544