BSD 4_3_Net_2 release

[unix-history] / usr / src / sbin / ping / ping.8

diff --git a/usr/src/sbin/ping/ping.8 b/usr/src/sbin/ping/ping.8
index db9e4be..4232217 100644 (file)
--- a/usr/src/sbin/ping/ping.8
+++ b/usr/src/sbin/ping/ping.8
@@ -1,129 +1,160 @@
-.\" Copyright (c) 1985 The Regents of the University of California.
+.\" Copyright (c) 1985, 1991 The Regents of the University of California.

 .\" All rights reserved.
 .\"
 .\" All rights reserved.
 .\"

-.\" Redistribution and use in source and binary forms are permitted provided
-.\" that: (1) source distributions retain this entire copyright notice and
-.\" comment, and (2) distributions including binaries display the following
-.\" acknowledgement:  ``This product includes software developed by the
-.\" University of California, Berkeley and its contributors'' in the
-.\" documentation or other materials provided with the distribution and in
-.\" all advertising materials mentioning features or use of this software.
-.\" 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
-.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
-.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+.\" 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.

 .\"
 .\"

-.\"    @(#)ping.8      6.6 (Berkeley) 6/24/90
+.\" 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.

 .\"
 .\"

-.TH PING 8 "June 24, 1990"
-.UC 6
-.SH NAME
-ping \- send ICMP ECHO_REQUEST packets to network hosts
-.SH SYNOPSIS
-.B ping
-[
-.B -dfnqrvR
-][
-.B -c
-count][
-.B -i
-wait][
-.B -l
-preload][
-.B -p
-pattern][
-.B -s
-packetsize]
-.SH DESCRIPTION
-.I Ping
+.\"     @(#)ping.8     6.7 (Berkeley) 3/16/91
+.\"
+.Dd March 16, 1991
+.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 dfnqrvR
+.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
+.Sh DESCRIPTION
+.Nm Ping

 uses the
 uses the

-ICMP protocol's mandatory ECHO_REQUEST datagram to elicit an
-ICMP ECHO_RESPONSE from a host or gateway.
-ECHO_REQUEST datagrams (``pings'') have an IP and ICMP header,
+.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
 followed by a

-.I struct timeval
+.Dq struct timeval

 and then an arbitrary number of ``pad'' bytes used to fill out the
 packet.
 The options are as follows:
 Other options are:
 and then an arbitrary number of ``pad'' bytes used to fill out the
 packet.
 The options are as follows:
 Other options are:

-.TP
-.I "-c count"
+.Bl -tag -width Ds
+.It Fl c Ar count

 Stop after sending (and receiving)
 Stop after sending (and receiving)

-.I count
-ECHO_RESPONSE packets.
-.TP
-.I -d
-Set the SO_DEBUG option on the socket being used.
-.TP
-.I -f
+.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.
 Flood ping.
 Outputs packets as fast as they come back or one hundred times per second,
 whichever is more.

-For every ECHO_REQUEST sent a period ``.'' is printed, while for ever
-ECHO_REPLY received a backspace is printed.
+For every
+.Tn ECHO_REQUEST
+sent a period ``.'' is printed, while for ever
+.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.
 This provides a rapid display of how many packets are being dropped.
 Only the super-user may use this option.

-.I "This can be very hard on a network and should be used with caution."
-.TP
-.I "-i wait"
+.Bf -emphasis
+This can be very hard on a network and should be used with caution.
+.Ef
+.It Fl i Ar wait

 Wait
 Wait

-.I wait seconds between sending each packet.
+.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
 The default is to wait for one second between each packet.
 This option is incompatible with the

-.I -f
+.Fl f

 option.
 option.

-.TP
-.I -l preload
+.It Fl l Ar preload

 If
 If

-.I preload
+.Ar preload

 is specified,
 is specified,

-.I ping
+.Nm ping

 sends that many packets as fast as possible before falling into its normal
 mode of behavior.
 sends that many packets as fast as possible before falling into its normal
 mode of behavior.

-.TP
-.I -n
+.It Fl n

 Numeric output only.
 No attempt will be made to lookup symbolic names for host addresses.
 Numeric output only.
 No attempt will be made to lookup symbolic names for host addresses.

-.TP
-.I "-p pattern"
+.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.
 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, ``-p ff'' will cause the sent packet to be filled with all
+For example,
+.Dq Li \-p ff
+will cause the sent packet to be filled with all

 ones.
 ones.

-.TP
-.I -q
+.It Fl q

 Quiet output.
 Nothing is displayed except the summary lines at startup time and
 when finished.
 Quiet output.
 Nothing is displayed except the summary lines at startup time and
 when finished.

-.TP
-.B -R
+.It Fl R

 Record route.
 Record route.

-Includes the RECORD_ROUTE option in the ECHO_REQUEST packet and displays
+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.
 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.

-.TP
-.I -r
+.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
 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

-.IR routed (8)).
-.TP
-.I "-s packetsize"
+.Xr routed 8 ) .
+.It Fl s Ar packetsize

 Specifies the number of data bytes to be sent.  
 Specifies the number of data bytes to be sent.  

-The default is 56, which translates into 64 ICMP data bytes when combined
-with the 8 bytes of ICMP header data.
-.TP
-.I -v
+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.
 Verbose output.

-ICMP packets other than ECHO_RESPONSE that are received are listed.
-.PP
+.Tn ICMP
+packets other than
+.Tn ECHO_RESPONSE
+that are received are listed.
+.El
+.Pp

 When using
 When using

-.I ping
+.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''.
 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''.


@@ -132,45 +163,56 @@ 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
 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 SIGINT, a brief summary is displayed.
-.PP
+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
 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

-.I ping
+.Nm ping

 during normal operations or from automated scripts.
 during normal operations or from automated scripts.

-.SH ICMP PACKET DETAILS
+.Sh ICMP PACKET DETAILS

 An IP header without options is 20 bytes.
 An IP header without options is 20 bytes.

-An ICMP ECHO_REQUEST packet contains an additional 8 bytes worth
-of ICMP header followed by an arbitrary amount of data.
+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
 When a

-.I packetsize
+.Ar packetsize

 is given, this indicated the size of this extra piece of data (the
 default is 56).
 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 ICMP
-ECHO_REPLY will always be 8 bytes more than the requested data space
-(the ICMP header).
-.PP
+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,
 If the data space is at least eight bytes large,

-.I ping
+.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.
 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
-.I Ping
+.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.
 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
+.Pp

 Damaged packets are obviously serious cause for alarm and often
 indicate broken hardware somewhere in the
 Damaged packets are obviously serious cause for alarm and often
 indicate broken hardware somewhere in the

-.I ping
+.Nm ping

 packet's path (in the network or in the hosts).
 packet's path (in the network or in the hosts).

-.SH TRYING DIFFERENT DATA PATTERNS
+.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
 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


@@ -182,66 +224,105 @@ 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.
 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
+.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
 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 \fI-p\fR option of \fIping\fR.
-.SH TTL DETAILS
-The TTL value of an IP packet represents the maximum number of IP routers
+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
 that the packet can go through before being thrown away.
 In current practice you can expect each router in the Internet to decrement

-the TTL field by exactly one.
-.PP
-The TCP/IP specification states that the TTL field for TCP packets should
-be set to 60, but many systems use smaller values (4.3 BSD uses 30, 4.2 used
+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).
 15).

-.PP
+.Pp

 The maximum possible value of this field is 255, and most Unix systems set
 The maximum possible value of this field is 255, and most Unix systems set

-the TTL field of ICMP ECHO_REQUEST packets to 255.
+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
 This is why you will find you can ``ping'' some hosts, but not reach them
 with

-.I telnet
+.Xr telnet 1

 or
 or

-.IR ftp .
-.PP
+.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
 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 TTL field in its response:
-.TP
---
-Not change it; this is what Berkeley Unix systems did before the 4.3BSD-tahoe
+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.
 release.

-In this case the TTL value in the received packet will be 255 minus the
+In this case the
+.Tn TTL
+value in the received packet will be 255 minus the

 number of routers in the round-trip path.
 number of routers in the round-trip path.

-.TP
---
+.It

 Set it to 255; this is what current Berkeley Unix systems do.
 Set it to 255; this is what current Berkeley Unix systems do.

-In this case the TTL value in the received packet will be 255 minus the
+In this case the
+.Tn TTL
+value in the received packet will be 255 minus the

 number of routers in the path
 number of routers in the path

-.I from
+.Xr from

 the remote system
 the remote system

-.I to
+.Em to

 the
 the

-.IR ping ing
+.Nm ping Ns Em ing

 host.
 host.

-.TP
---
+.It

 Set it to some other value.
 Set it to some other value.

-Some machines use the same value for ICMP packets that they use for
-TCP packets, for example either 30 or 60.
+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.
 Others may use completely wild values.

-.SH BUGS
-Many Hosts and Gateways ignore the RECORD_ROUTE option.
-.PP
-The maximum IP header length is too small for options like RECORD_ROUTE to
+.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.
 be completely useful.
 There's not much that that can be done about this, however.

-.PP
+.Pp

 Flood pinging is not recommended in general, and flood pinging the
 broadcast address should only be done under very controlled conditions.
 Flood pinging is not recommended in general, and flood pinging the
 broadcast address should only be done under very controlled conditions.

-.SH SEE ALSO
-netstat(1), ifconfig(8), routed(8)
+.Sh SEE ALSO
+.Xr netstat 1 ,
+.Xr ifconfig 8 ,
+.Xr routed 8
+.Sh HISTORY
+The
+.Nm
+command appeared in
+.Bx 4.3 .