.TH PING 8
.SH NAME
ping, gping, traceroute \- probe the Internet
.SH SYNOPSIS
.B ping
[
.B -d
] [
.B -i
.I interval
] [
.B -s
.I size
] [
.B -n
.I count
]
.I destination
.PP
.B gping
[
.B -r
] [
.B -l
] [
.B -i
.I interval
]
.I destination
[
.I destination
\&... ]
.PP
.B traceroute
[
.B -dn
][
.B -t
.I tries
]
.I dest
.SH DESCRIPTION
.I Ping
sends ICMP echo requests to a system and returns the time
for a response.  It can be used to determine the network delay
and whether or not the destination is up.
.PP
The options are:
.TP
.B n
requests that a total of
.I count
messages be sent, default 32.
.TP
.B i
sets the time between messages
to be
.I interval
milliseconds, default 1000 ms.
.TP
.B s
sets the length of the message to be
.I size
bytes, ICMP header included.
The size cannot be smaller than 32 or
larger than 8192.  The default is
64.
.TP
.B d
causes message numbers to be printed
so that one can see the order with which
messages are received and which are lost.
.PP
.I Gping
is a
.I ping
with a graphical display.  It
presents separate graphs for each destination
specified.
.PP
The options are:
.TP
.B r
display round trip time in seconds.
This is the default.
.TP
.B l
display percentage of lost messages.
A message is considered lost if not
replied to in 10 seconds.  The percentage
is an exponentially weighted average.
.TP
.B i
sets the time between messages
to be
.I interval
milliseconds, default 5000 ms.
.PP
Graphs can be dropped and added using
the button 3 menu.  Clicking button 1
on a datapoint displays the value of the
datapoint and the time it was recorded.
.PP
.I Traceroute
displays the IP addresses and average round trip times to all
routers between the machine it is run on and
.IR dest .
It does this by sending packets to
.I dest
with increasing times to live (TTL) in their headers.
Each router that a packet expires at replies with an ICMP
warning message.
The options are:
.TP
.B d
print debugging to standard error
.TP
.B n
just print out IP numbers, don't try to
look up the names of the routers.
.TP
.B t
send
.I tries
packets at each TTL value (default 1).
.SH SOURCE
.B /sys/src/cmd/ip/ping.c
.br
.B /sys/src/cmd/ip/gping.c
.br
.B /sys/src/cmd/ip/traceroute.c