PING(1M-SysV)       RISC/os Reference Manual        PING(1M-SysV)



NAME
     ping - send ICMP ECHO_REQUEST packets to network hosts

SYNOPSIS
     /etc/ping [ -r ] [ -v ] host [ packetsize ] [ count ]

DESCRIPTION
     The DARPA Internet is a large and complex aggregation of
     network hardware, connected together by gateways.  Tracking
     a single-point hardware or software failure can often be
     difficult.  ping utilizes 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, followed by a struct timeval, and then
     an arbitrary number of ``pad'' bytes used to fill out the
     packet.  Default datagram length is 64 bytes, but this may
     be changed using the command-line option.  Other options
     are:

     -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
                         routed(1M) ).

     -v                  Verbose output.  ICMP packets other than
                         ECHO_RESPONSE that are received are
                         listed.

     When using ping for fault isolation, it should first be run
     on the local host, to verify that the local network inter-
     face is up and running.  Then, hosts and gateways further
     and further away should be ``pinged''.  ping sends one
     datagram per second, and prints one line of output for every
     ECHO_RESPONSE returned.  No output is produced if there is
     no response.  If an optional count is given, only that
     number of requests is sent.  Round-trip times and packet
     loss statistics are computed.  When all responses have been
     received or the program times out (with a count specified),
     or if the program is terminated with a SIGINT, a brief sum-
     mary is displayed.

     This program is intended for use in network testing, meas-
     urement and management.  It should be used primarily for
     manual fault isolation.  Because of the load it could impose
     on the network, it is unwise to use ping during normal
     operations or from automated scripts.




                         Printed 1/15/91                   Page 1

PING(1M-SysV)       RISC/os Reference Manual        PING(1M-SysV)



AUTHOR
     Mike Muuss

SEE ALSO
     netstat(1), ifconfig(1M)


















































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