= ping: probe the Internet

== SYNOPSIS

*ip/ping* [*-alq*] [ **-i**__ interval__ ] [ **-s**__ size__ ] [
**-n**__ nping__ ] _destination_


_Ping_ sends ICMP echo requests to a network _destination_ (which has
the syntax accepted by _dial_(2)). The target host, if up, should send a
corresponding reply. By default, one line is printed for each reply,
containing the sequence number (starting at 0) of the message it
answers, the round trip time for that reply, the average round trip time
so far, and the `time to live' value from the reply packet.

The options are:

*-a*::
  include source and destination IP addresses in the output
**-i**__ interval__::
  send requests with the given _interval_ between messages, in
  milliseconds (default: 1 second)
*-l*::
  list only lost messages
**-n**__ nping__::
  send _nping_ messages in all (default: 32)
*-q*::
  suppress per-packet output, giving summary data only
**-s**__ size__::
  send request packets of the given _size_ in bytes (default: 64,
  minimum 32)

== SOURCE

*/appl/cmd/ip/ping.b*

== SEE ALSO

_dial_(2), _ip_(3)

== DIAGNOSTICS

_Ping_ yields an error status if any request had no corresponding reply.

== BUGS

Works only on native Inferno and when hosted on Plan 9, owing to the
lack of access to ICMP on other hosted systems.