PING(8)PING(8)NAMEping - send ICMP ECHO_REQUEST packets to network hosts
SYNOPSIS
/usr/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(8C)).
-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''. 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 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.
AUTHOR
Mike Muuss
SEE ALSOnetstat(1), ifconfig(8C)4.3 Berkeley Distribution May 23, 1986 PING(8)
