PING(8)                                                                PING(8)



NAME
       ping - send ICMP ECHO_REQUEST packets to network hosts

SYNOPSIS
       /etc/ping [ -r ] [ -v ] _h_o_s_t [ _p_a_c_k_e_t_s_i_z_e ] [ _c_o_u_n_t ]

DESCRIPTION
       The  DARPA Internet is a large and complex aggregation of network hard‐
       ware, connected together by gateways.  Tracking a single-point hardware
       or  software  failure  can  often be difficult.  _P_i_n_g 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 _r_o_u_t_e_d(8C)).

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

       When using _p_i_n_g for fault isolation, it should  first  be  run  on  the
       local  host,  to verify that the local network interface is up and run‐
       ning.  Then, hosts and gateways further  and  further  away  should  be
       ‘‘pinged’’.  _P_i_n_g 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 _c_o_u_n_t 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 _c_o_u_n_t specified), or if the program is  terminated  with  a
       SIGINT, 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
       _p_i_n_g during normal operations or from automated scripts.

AUTHOR
       Mike Muuss

SEE ALSO
       netstat(1), ifconfig(8C)



4.3 Berkeley Distribution        May 23, 1986                          PING(8)