PING(ADMN)                                 UNIX System V



     Name
          ping - send ICMP ECHO_REQUEST packets to network hosts


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


     Description
          ping is a troubleshooting tool for tracking  a  single-point
          hardware  or  software failure in the Internet.  It 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 an ICMP  header,  followed
          by  a  struct  timeval  and 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.

          -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
          interface is up  and  running.   Then,  hosts  and  gateways
          further  and  further  away should be pinged.  The ping tool
          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 are out (with a
          count specified), or if the program  is  terminated  with  a
          SIGINT, then a brief summary is displayed.

          This  program  is  intended  for  use  in  network  testing,
          measurement 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.


     See Also
          netstat(TC), ifconfig(ADMN).


     (printed 8/17/89)                                  PING(ADMN)