10.2;ping, revision 2.0, 89/03/31
ping -send ICMP ECHO_REQUEST packets to network hosts
usage: /etc/ping [-d] [-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. The ping program
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.
When using ping for fault isolation, you should first run it 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".
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 you specify an optional count, 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, ping displays
a brief summary.
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.
OPTIONS
Other options are:
-d Display debugging information.
-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.
-v Verbose output. List ICMP packets other than ECHO RESPONSE that are
received.
SEE ALSO
ifconfig, netstat;
Configuring and Managing TCP/IP.