=head1 NAME

oping - send ICMP ECHO_REQUEST to network hosts

=head1 SYNOPSIS

B<oping> [B<-4> | B<-6>] [B<-c> I<count>] [B<-i> I<interval>] I<host> [I<host> [I<host> ...]]

B<oping> [B<-4> | B<-6>] [B<-c> I<count>] [B<-i> I<interval>] B<-f> I<filename>

B<noping> [B<-4> | B<-6>] [B<-c> I<count>] [B<-i> I<interval>] I<host> [I<host> [I<host> ...]]

B<noping> [B<-4> | B<-6>] [B<-c> I<count>] [B<-i> I<interval>] B<-f> I<filename>

=head1 DESCRIPTION

B<oping> uses ICMPv4 or ICMPv6 ECHO_REQUEST packets to measure a hosts
reachability and the network latency. In contrast to the original L<ping(8)>
utility B<oping> can send ICMP packets to multiple hosts in parallel and wait
for all ECHO_RESPONSE packets to arrive. In contrast to the B<fping> utility
(URL is listed in L<"SEE ALSO">) B<oping> can use both, IPv4 and IPv6
transparently and side by side.

B<noping> is an ncurses-based front-end to I<liboping> which displays ping
statistics online and highlights aberrant round-trip times if the terminal
supports colors.

=head1 OPTIONS

=over 4

=item B<-4>

Force the use of IPv4. 

=item B<-6>

Force the use of IPv6.

=item B<-c> I<count>

Send (and receive) I<count> ICMP packets, then stop and exit.

=item B<-i> I<interval>

Send one ICMP packet (per host) each I<interval> seconds. This can be a
floating-point number to specify sub-second precision.

=item B<-t> I<ttl>

Set the IP Time to Live to I<ttl>. This must be a number between (and
including) 1E<nbsp>andE<nbsp>255. If omitted, the value B<64> is used.

=item B<-I> I<address>

Set the source address to use. You may either specify an IP number or a
hostname. You B<cannot> pass the interface name, as you can with GNU's
L<ping(8)> - use the B<-D> option for that purpose.

=item B<-D> I<interface name>

Set the outgoing network device to use.

=item B<-f> I<filename>

Instead of specifying hostnames on the command line, read them from
I<filename>. If I<filename> is B<->, read from C<STDIN>.

If the real user ID (as returned by L<getuid(2)>) and the effective user ID (as
returned by L<geteuid(2)>) differ, the only argument allowed for this option is
"-" (i.E<nbsp>e. standard input). This is meant to avoid security issues when
I<oping> is installed with the SUID-bit.

=item B<-Q> I<qos>

Specify the I<Quality of Service> (QoS) for outgoing packets. This is a
somewhat tricky option, since the meaning of the bits in the IPv4 header has
been revised several times.

The currently recommended method is I<Differentiated Services> which is used in
IPv6 headers as well. There are shortcuts for 13E<nbsp>predefined
I<per-hop behaviors> (PHBs):

=over 4

=item B<be>

Selects the I<Best Effort> behavior. This is the default behavior.

=item B<ef>

Selects the I<Expedited Forwarding> (EF) per-hop behavior, as defined in
I<RFCE<nbsp>3246>. This PHB is characterised by low delay, low loss and low
jitter, i.e. high priority traffic.

=item B<va>

Selects the I<Voice Admitted> (VA) per-hop behavior, as defined in
I<RFCE<nbsp>5865>. This traffic class is meant for I<Voice over IP> (VoIP)
traffic which uses I<Call Admission Control> (CAC) for reserving network
capacity.

=item  B<af>I<c>I<p>

Selects one of 12E<nbsp>differentiated services code points (DSCPs), which are
organized in four I<classes> with three I<priorities> each. Therefore, I<c>
must be a number betweenE<nbsp>1 throughE<nbsp>4 and I<p> must be a number
betweenE<nbsp>1 throughE<nbsp>3, for example "af13", "af22" and "af41". In each
class, the lower priority number takes precedence over the higher priority
number.

=item B<cs>I<n>

Selects one of the eight I<Class Selector> PHBs. I<n> is a number
betweenE<nbsp>0 throughE<nbsp>7. The class selectors have been defined to be
compatible to the I<Precedence> field in the IPv4 header as defined in
I<RFCE<nbsp>791>. Please note that "cs0" is synonymous to "be".

=back

The old definition of the same bits in the IPv4 header was as I<Type of
Service> (ToS) field, specified in I<RFCE<nbsp>1349>. It defined four possible
values which have appropriate aliases. Please note that this use of the bits is
B<deprecated> and the meaning is limited to IPv4!

=over 4

=item B<lowdelay>

Minimize delay

=item B<throughput>

Maximize throughput

=item B<reliability>

Maximize reliability

=item B<mincost>

Minimize monetary cost

=back

Alternatively, you can also specify the byte manually. You can use either a
decimal number (0-255), a hexadecimal number (0x00-0xff) or an octal number
(00-0377) using the usual "0x" and "0" prefixes for hexadecimal and octal
respectively.

The printed lines will contain information about the QoS field of received
packets if either a non-standard QoS setting was used on outgoing packets or if
the QoS byte of incoming packets is not zero. In other words, the QoS
information is omitted if both, the outgoing and the incoming QoS bytes are
zero. The received byte is always interpreted as
I<Differentiated Services Code Point> (DSCP) and
I<Explicit Congestion Notification> (ECN), even if the deprecated
I<Type of Service> (ToS) aliases were used to specify the bits of outgoing
packets.

=back

=head1 COLORS

If supported by the terminal, I<noping> will highlight the round-trip times
(RTT) using the colors green, yellow and red. Green signals RTTs that are in
the "expected" range, yellow marks moderately unusual times and times that
differ a lot from the expected value are printed in red.

The information used to categorize round-trip times is the I<average>
round-trip time and the I<standard deviation>. RTTs that differ from the
average by less than the standard deviation are considered to be "normal" and
are printed in green. Times that differ from the average more than the standard
deviation but less than twice the standard deviation are considered "moderately
unusual" and are printed in yellow. Times differing more than twice the
standard deviation from the average are considered to be "unusual" and are
printed in red.

=head1 SEE ALSO

L<ping(8)>, L<http://www.fping.com/>, L<liboping(3)>

=head1 AUTHOR

liboping is written by Florian octo Forster E<lt>octo at verplant.orgE<gt>.
Its homepage can be found at L<http://verplant.org/liboping/>.

(c) 2005-2010 by Florian octo Forster.