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diff --git a/debian/local/man/ping.8 b/debian/local/man/ping.8 new file mode 100644 index 0000000..2382365 --- /dev/null +++ b/debian/local/man/ping.8 @@ -0,0 +1,328 @@ +.\" Copyright (c) 1985, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)ping.8 8.3 (Berkeley) 4/28/95 +.\" +.Dd April 28, 1995 +.Dt PING 8 +.Os BSD 4.3 +.Sh NAME +.Nm ping +.Nd send +.Tn ICMP ECHO_REQUEST +packets to network hosts +.Sh SYNOPSIS +.Nm ping +.Op Fl Rdfnqrv +.Op Fl c Ar count +.Op Fl i Ar wait +.Op Fl l Ar preload +.Op Fl p Ar pattern +.Op Fl s Ar packetsize +.Ar host +.Sh DESCRIPTION +.Nm Ping +uses the +.Tn ICMP +protocol's mandatory +.Tn ECHO_REQUEST +datagram to elicit an +.Tn ICMP ECHO_RESPONSE +from a host or gateway. +.Tn ECHO_REQUEST +datagrams (``pings'') have an IP and +.Tn ICMP +header, +followed by a +.Dq struct timeval +and then an arbitrary number of ``pad'' bytes used to fill out the +packet. +The options are as follows: +.Bl -tag -width Ds +.It Fl c Ar count +Stop after sending (and receiving) +.Ar count +.Tn ECHO_RESPONSE +packets. +.It Fl d +Set the +.Dv SO_DEBUG +option on the socket being used. +.It Fl f +Flood ping. +Outputs packets as fast as they come back or one hundred times per second, +whichever is more. +For every +.Tn ECHO_REQUEST +sent a period ``.'' is printed, while for every +.Tn ECHO_REPLY +received a backspace is printed. +This provides a rapid display of how many packets are being dropped. +Only the super-user may use this option. +.Bf -emphasis +This can be very hard on a network and should be used with caution. +.Ef +.It Fl i Ar wait +Wait +.Ar wait +seconds +.Em between sending each packet . +The default is to wait for one second between each packet. +This option is incompatible with the +.Fl f +option. +.It Fl l Ar preload +If +.Ar preload +is specified, +.Nm ping +sends that many packets as fast as possible before falling into its normal +mode of behavior. +.It Fl n +Numeric output only. +No attempt will be made to lookup symbolic names for host addresses. +.It Fl p Ar pattern +You may specify up to 16 ``pad'' bytes to fill out the packet you send. +This is useful for diagnosing data-dependent problems in a network. +For example, +.Dq Li \-p ff +will cause the sent packet to be filled with all +ones. +.It Fl q +Quiet output. +Nothing is displayed except the summary lines at startup time and +when finished. +.It Fl R +Record route. +Includes the +.Tn RECORD_ROUTE +option in the +.Tn ECHO_REQUEST +packet and displays +the route buffer on returned packets. +Note that the IP header is only large enough for nine such routes. +Many hosts ignore or discard this option. +.It Fl r +Bypass the normal routing tables and send directly to a host on an attached +network. +If the host is not on a directly-attached network, an error is returned. +This option can be used to ping a local host through an interface +that has no route through it (e.g., after the interface was dropped by +.Xr routed 8 ) . +.It Fl s Ar packetsize +Specifies the number of data bytes to be sent. +The default is 56, which translates into 64 +.Tn ICMP +data bytes when combined +with the 8 bytes of +.Tn ICMP +header data. +.It Fl v +Verbose output. +.Tn ICMP +packets other than +.Tn ECHO_RESPONSE +that are received are listed. +.El +.Pp +When using +.Nm ping +for fault isolation, it should first be run on the local host, to verify +that the local network interface is up and running. +Then, hosts and gateways further and further away should be ``pinged''. +Round-trip times and packet loss statistics are computed. +If duplicate packets are received, they are not included in the packet +loss calculation, although the round trip time of these packets is used +in calculating the minimum/average/maximum round-trip time numbers. +When the specified number of packets have been sent (and received) or +if the program is terminated with a +.Dv SIGINT , +a brief summary is displayed. +.Pp +This program is intended for use in network testing, measurement and +management. +Because of the load it can impose on the network, it is unwise to use +.Nm ping +during normal operations or from automated scripts. +.Sh ICMP PACKET DETAILS +An IP header without options is 20 bytes. +An +.Tn ICMP +.Tn ECHO_REQUEST +packet contains an additional 8 bytes worth +of +.Tn ICMP +header followed by an arbitrary amount of data. +When a +.Ar packetsize +is given, this indicated the size of this extra piece of data (the +default is 56). +Thus the amount of data received inside of an IP packet of type +.Tn ICMP +.Tn ECHO_REPLY +will always be 8 bytes more than the requested data space +(the +.Tn ICMP +header). +.Pp +If the data space is at least eight bytes large, +.Nm ping +uses the first eight bytes of this space to include a timestamp which +it uses in the computation of round trip times. +If less than eight bytes of pad are specified, no round trip times are +given. +.Sh DUPLICATE AND DAMAGED PACKETS +.Nm Ping +will report duplicate and damaged packets. +Duplicate packets should never occur, and seem to be caused by +inappropriate link-level retransmissions. +Duplicates may occur in many situations and are rarely (if ever) a +good sign, although the presence of low levels of duplicates may not +always be cause for alarm. +.Pp +Damaged packets are obviously serious cause for alarm and often +indicate broken hardware somewhere in the +.Nm ping +packet's path (in the network or in the hosts). +.Sh TRYING DIFFERENT DATA PATTERNS +The (inter)network layer should never treat packets differently depending +on the data contained in the data portion. +Unfortunately, data-dependent problems have been known to sneak into +networks and remain undetected for long periods of time. +In many cases the particular pattern that will have problems is something +that doesn't have sufficient ``transitions'', such as all ones or all +zeros, or a pattern right at the edge, such as almost all zeros. +It isn't necessarily enough to specify a data pattern of all zeros (for +example) on the command line because the pattern that is of interest is +at the data link level, and the relationship between what you type and +what the controllers transmit can be complicated. +.Pp +This means that if you have a data-dependent problem you will probably +have to do a lot of testing to find it. +If you are lucky, you may manage to find a file that either can't be sent +across your network or that takes much longer to transfer than other +similar length files. +You can then examine this file for repeated patterns that you can test +using the +.Fl p +option of +.Nm ping . +.Sh TTL DETAILS +The +.Tn TTL +value of an IP packet represents the maximum number of IP routers +that the packet can go through before being thrown away. +In current practice you can expect each router in the Internet to decrement +the +.Tn TTL +field by exactly one. +.Pp +The +.Tn TCP/IP +specification states that the +.Tn TTL +field for +.Tn TCP +packets should +be set to 60, but many systems use smaller values (4.3 +.Tn BSD +uses 30, 4.2 used +15). +.Pp +The maximum possible value of this field is 255, and most Unix systems set +the +.Tn TTL +field of +.Tn ICMP ECHO_REQUEST +packets to 255. +This is why you will find you can ``ping'' some hosts, but not reach them +with +.Xr telnet 1 +or +.Xr ftp 1 . +.Pp +In normal operation ping prints the ttl value from the packet it receives. +When a remote system receives a ping packet, it can do one of three things +with the +.Tn TTL +field in its response: +.Bl -bullet +.It +Not change it; this is what Berkeley Unix systems did before the +.Bx 4.3 tahoe +release. +In this case the +.Tn TTL +value in the received packet will be 255 minus the +number of routers in the round-trip path. +.It +Set it to 255; this is what current Berkeley Unix systems do. +In this case the +.Tn TTL +value in the received packet will be 255 minus the +number of routers in the path +.Xr from +the remote system +.Em to +the +.Nm ping Ns Em ing +host. +.It +Set it to some other value. +Some machines use the same value for +.Tn ICMP +packets that they use for +.Tn TCP +packets, for example either 30 or 60. +Others may use completely wild values. +.El +.Sh BUGS +Many Hosts and Gateways ignore the +.Tn RECORD_ROUTE +option. +.Pp +The maximum IP header length is too small for options like +.Tn RECORD_ROUTE +to +be completely useful. +There's not much that that can be done about this, however. +.Pp +Flood pinging is not recommended in general, and flood pinging the +broadcast address should only be done under very controlled conditions. +.Sh SEE ALSO +.Xr netstat 1 , +.Xr ifconfig 8 , +.Xr routed 8 +.Sh HISTORY +The +.Nm +command appeared in +.Bx 4.3 . |