doc::smokeping::probes::tcpping(3)
NAME
Smokeping::probes::TCPPing - TCPPing Probe for SmokePing
SYNOPSIS
*** Probes *** +TCPPing binary = /usr/bin/tcpping # mandatory forks = 5 offset = 50% step = 300 timeout = 15 # The following variables can be overridden in each target section pings = 5 port = 80 # [...] *** Targets *** probe = TCPPing # if this should be the default probe # [...] + mytarget # probe = TCPPing # if the default probe is something else host = my.host pings = 5 port = 80
DESCRIPTION
Integrates TCPPing as a probe into smokeping. The variable binary must
point to your copy of the TCPPing program. If it is not installed on
your system yet, you can get it from
http://www.vdberg.org/~richard/tcpping. You can also get it from
http://www.darkskies.za.net/~norman/scripts/tcpping.
The (optional) port option lets you configure the port for the pings
sent. The TCPPing manpage has the following to say on this topic:
The problem is that with the widespread use of firewalls on the modern
Internet, many of the packets that traceroute(8) sends out end up being
filtered, making it impossible to completely trace the path to the
destination. However, in many cases, these firewalls will permit
inbound TCP packets to specific ports that hosts sitting behind the
firewall are listening for connections on. By sending out TCP SYN
packets instead of UDP or ICMP ECHO packets, tcptraceroute is able to
bypass the most common firewall filters.
It is worth noting that tcptraceroute never completely establishes a
TCP connection with the destination host. If the host is not listening
for incoming connections, it will respond with an RST indicating that
the port is closed. If the host instead responds with a SYN|ACK, the
port is known to be open, and an RST is sent by the kernel
tcptraceroute is running on to tear down the connection without
completing three-way handshake. This is the same half-open scanning
technique that nmap(1) uses when passed the -sS flag.
VARIABLES
Supported probe-specific variables:
- binary
- The location of your TCPPing script.
- Example value: /usr/bin/tcpping
- This setting is mandatory.
- forks
- Run this many concurrent processes at maximum
- Example value: 5
- Default value: 5
- offset
- If you run many probes concurrently you may want to prevent them
from hitting your network all at the same time. Using the probespecific offset parameter you can change the point in time when
each probe will be run. Offset is specified in % of total interval, or alternatively as 'random', and the offset from the 'General'
section is used if nothing is specified here. Note that this does
NOT influence the rrds itself, it is just a matter of when data
acqusition is initiated. (This variable is only applicable if the variable 'concurrentprobes' is set in the 'General' section.) - Example value: 50%
- step
- Duration of the base interval that this probe should use, if
different from the one specified in the 'Database' section. Note
that the step in the RRD files is fixed when they are originally
generated, and if you change the step parameter afterwards, you'll have to delete the old RRD files or somehow convert them. (This
variable is only applicable if the variable 'concurrentprobes' is
set in the 'General' section.) - Example value: 300
- timeout
- How long a single 'ping' takes at maximum
- Example value: 15
- Default value: 5
- Supported target-specific variables:
- pings
- How many pings should be sent to each target, if different from the
global value specified in the Database section. Note that the
number of pings in the RRD files is fixed when they are originally generated, and if you change this parameter afterwards, you'll have to delete the old RRD files or somehow convert them. - Example value: 5
- port
- The TCP port the probe should measure.
- Example value: 80
AUTHORS
- Norman Rasmussen <norman@rasmussen.org> Patched for Smokeping 2.x
compatibility by Anton Chernev <maznio@doom.bg>