oping (8) - Linux Manuals
oping: send ICMP ECHO_REQUEST to network hosts
oping - send ICMP ECHO_REQUEST to network hosts
SYNOPSISoping [-4 | -6] [-c count] [-i interval] host [host [host ...]]
oping [-4 | -6] [-c count] [-i interval] -f filename
noping [-4 | -6] [-c count] [-i interval] host [host [host ...]]
DESCRIPTIONoping uses ICMPv4 or ICMPv6 ECHO_REQUEST packets to measure a hosts reachability and the network latency. In contrast to the original ping(8) utility oping can send ICMP packets to multiple hosts in parallel and wait for all ECHO_RESPONSE packets to arrive. In contrast to the fping utility (URL is listed in ``SEE ALSO'') oping can use both, IPv4 and IPv6 transparently and side by side.
- Force the use of IPv4.
- Force the use of IPv6.
- -c count
- Send (and receive) count ICMP packets, then stop and exit.
- -i interval
- Send one ICMP packet (per host) each interval seconds. This can be a floating-point number to specify sub-second precision.
- -t ttl
- Set the IP Time to Live to ttl. This must be a number between (and including) 1 and 255. If omitted, the value 64 is used.
- -I address
- Set the source address to use. You may either specify an IP number or a hostname. You cannot pass the interface name, as you can with GNU's ping(8) - use the -D option for that purpose.
- -D interface name
- Set the outgoing network device to use.
- -f filename
Instead of specifying hostnames on the command line, read them from
filename. If filename is -, read from "STDIN".
If oping is installed with the SetUID-bit, it will set the effective UID to the real UID before opening the file. In the special (but common) case that oping is owned by the super-user (UID
0), this means that privileges are temporarily dropped before opening the file, in order to prevent users from reading arbitrary files on the system.
If your system doesn't provide saved set-user IDs (this was an optional feature before POSIX
2001), the behavior is different because it is not possible to temporarily drop privileges. The alternative behavior is: If the real user ID (as returned by getuid(2)) and the effective user ID (as returned by geteuid(2)) differ, the only argument allowed for this option is ``-'' (i.e. standard input).
- -Q qos
Specify the 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 Differentiated Services which is used in IPv6 headers as well. There are shortcuts for various predefined per-hop behaviors (PHBs):
- Selects the Best Effort behavior. This is the default behavior.
Selects the Expedited Forwarding (EF) per-hop behavior, as defined in
3246. This PHB is characterised by low delay, low loss and low jitter, i.e. high priority traffic.
Selects the Voice Admitted (VA) per-hop behavior, as defined in
5865. This traffic class is meant for Voice over IP (VoIP) traffic which uses Call Admission Control (CAC) for reserving network capacity.
- Selects one of 12 differentiated services code points (DSCPs), which are organized in four classes with three priorities each. Therefore, c must be a number between 1 through 4 and p must be a number between 1 through 3, for example ``af13'', ``af22'' and ``af41''. In each class, the lower priority number takes precedence over the higher priority number.
Selects one of the eight Class Selector PHBs. n is a number
between 0 through 7. The class selectors have been defined to be
compatible to the Precedence field in the IPv4 header as defined in
791. Please note that ``cs0'' is synonymous to ``be''.
The old definition of the same bits in the IPv4 header was as Type of Service (ToS) field, specified in RFC
1349. It defined four possible values which have appropriate aliases. Please note that this use of the bits is deprecated and the meaning is limited to IPv4!
- Minimize delay
- Maximize throughput
- Maximize reliability
- Minimize monetary cost
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 Differentiated Services Code Point (DSCP) and Explicit Congestion Notification (ECN), even if the deprecated Type of Service (ToS) aliases were used to specify the bits of outgoing packets.
COLORSIf supported by the terminal, 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 average round-trip time and the 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.
AUTHORliboping is written by Florian ``octo'' Forster <ff at octo.it>. Its homepage can be found at <http://verplant.org/liboping/>.
Copyright (c) 2005-2011 by Florian ``octo'' Forster.