.TH PING 8
.SH NAME
ping, gping, traceroute, hogports \- probe the Internet
.SH SYNOPSIS
.B ip/ping
[
.B -6aflqr
] [
.B -i
.I interval
] [
.B -n
.I count
] [
.B -s
.I size
] [
.B -w
.I waittime
]
.I destination
.PP
.B ip/gping
[
.B -r
] [
.B -l
] [
.B -i
.I interval
]
.I destination
[
.I destination
\&... ]
.PP
.B ip/traceroute
[
.B -dn
][
.B -a
.I n
][
.B -h
.I nbuck
][
.B -t
.I sttl
]
.I dest
.PP
.B ip/hogports
.B [\fImtpt\fP/]\fIproto\fP!\fIaddress\fP!\fIstartport\fP[-\fIendport\fP]
.SH DESCRIPTION
.I Ping
sends ICMP echo request messages to a system.
It can be used to determine the network delay
and whether or not the destination is up.
By default, a line is written to standard output for
each request.
If a reply is received the line contains the request
id (starting at 0 and incrementing), the round trip time
for this request, the average round trip time, and the time
to live in the reply packet.  If no reply is received the line
contains the word "lost", the request id, and the average round
trip time.
.PP
If a reply is received for each request,
.I ping
returns successfully. Otherwise it returns an error status of
"lost messages".
.PP
The options are:
.TP
.B 6
force the use of IPv6's ICMP,
.BR icmpv6 ,
instead of IPv4's ICMP.
.I Ping
tries to determine which version of IP to use automatically.
.TP
.B a
adds the IP source and destination addresses to each report.
.TP
.B f
send messages as fast as possible (flood). This flag
is not compatable with
.BR -r .
.TP
.B i
sets the time between messages
to be
.I interval
milliseconds, default 1000 ms.
.TP
.B l
causes only lost messages to be reported.
.TP
.B n
requests that a total of
.I count
messages be sent, default 32.
.TP
.B q
suppresses any output (i.e. be quiet).
.TP
.B r
randomizes the delay with a minimum extra delay of 0 ms and a
maximum extra delay of the selected interval. This flag
is not compatable with
.BR -f .
.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 w
sets the additional time in milliseconds to wait
after all packets are sent.
.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 a
make
.I n
attempts at each TTL value (default 3).
.TP
.B t
set the starting TTL value to
.I sttl
(default 1).
.TP
.B h
print out a histogram of times from request
to response at each TTL value.  The histogram
contains
.I nbuck
buckets.
.PD
.PP
.I Hogports
announces on a range of ports to keep them from other processes.
For example, to keep anyone from making a vncserver visible on
the network mounted at
.BR /net.alt :
.EX

	ip/hogports /net.alt/tcp!*!5900-5950
.EE
.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
.br
.B /sys/src/cmd/ip/hogports.c
.SH SEE ALSO
.IR ip (3)