.\" Copyright (c) 1985 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)ping.8	6.1 (Berkeley) %G%
.\"
.TH PING 8 ""
.UC 6
.SH NAME
ping \- send ICMP ECHO_REQUEST packets to network hosts
.SH SYNOPSIS
.B /etc/ping
.B host
[
.B packetsize
]
.SH DESCRIPTION
The ARPA 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.
.I Ping
utilizes the mandatory
ICMP protocol's ECHO_REQUEST datagram to elicit an
ICMP ECHO_RESPONSE from a distant host or gateway.
ECHO_REQUEST datagrams (``pings'') have an IP and ICMP header,
followed by a \fBstruct timeval\fR, 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.
.PP
When using \fIping\fR 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''.  A lack of output from the \fIping\fR
program indicates no response;  in normal operation,
\fIping\fR sends one datagram per second, and
prints one line of output for every ECHO_RESPONSE returned.
Round-trip times and packet loss statistics are computed.
If the program is terminated with a SIGINT, a brief
summary is displayed.
.SH AUTHOR
Mike Muuss
.SH SEE ALSO
netstat(8),
ifconfig(5)