Como Instalar Nagios en Mandriva

Instalación y Configuración de Nagios 3.x en Mandriva 2008.0
Para instalar nagios deberemos instalar los pluguins a utilizar y apache como servidor web.
Abrimos una consola y ejecutamos urpmi nagios este comando nos pedirá instalar algunas dependencias que necesitara el paquete.
Luego en la misma consola ejecutameros urpmi nagios-check y se nos listaran todos los pluguins disponibles para el sistema. Una vez elegido el pluguin a instalar ejecutamos urpmi con el nombre del paquete, por ejemplo si necesitamos instalar check_nt se ejecutara urpmi nagios-check_nt
Luego instalaremos apache de la misma forma, urpmi apache, este comando nos dara a elegir entre distintas versiones de apache, generalmente se instala la versión estable
Estructura de archivos
El directorio etc/ de nagios quedaría con la siguiente disposición

cgi.cfg
nagios.cfg ---> Archivo de configuración general de nagios
objects ----> en este directorio están los archivos de definición de hosts y manejo de plugins y configuración de servicios a chequear
resource.cfg
Conf.d ----> en este directorio se encontrara el arhcivo de configuración de host y hostgroup del nagios.
Hostgroups

Hay tres grupos principales de Hosts, localhost que contiene solo el host local donde esta corriendo el servicio de nagios con apache, luego el grupo linux-servers donde se ubican todos los equipos linux, el grupo windows-servers donde están contenidos los equipos que funcionan con windows.
Para equipos Windows se puede ver el uso de memoria física, memoria virtual, servicios corriendo, uso de espacio en disco, uso de CPU.
Para equipos Linux se puede ver el uso de memoria física, memoria swap, procesos corriendo, uso de espacio en disco, carga de CPU, interfaces de red activas.
Servicios
Los servicios están clasificados en
local: para el localhost de nagios
generico: servicios comunes de respuesta para cualquier sistema, ej PING
linux: servicios solo a monitorear en sistemas linux
windows: monitoreos propios de windows
storage: lo referente a discos y almacenamiento
Commandos
Estan divididos en categorías similares a los servicios, aunque estos están divididos en genérico, local, windows,
snmp: comandos estandares SNMP soportados por Linux y Windows
Creando directivas
Debemos crear algunas entradas de configuración para especificar donde encontramos los servicios, grupos, contactos etc, las mismas debemos incluirlas en nuestro archivo de configuración nagios.cfg

# Directorio con la configuración de host y grupos de Hosts de los Servidores
cfg_dir=/etc/nagios/conf.d/nag.cfg 
# Directorio con la configuración de contactos
cfg_dir=/etc/nagios/objects/contacts
 
# Directorio con la configuración de servicios
cfg_dir=/ etc/nagios/objects/windows.cfg
# Directorio con la configuración de los comandos
cfg_dir=/etc/nagios/objects/commands.cfg
# Directorio con la configuración de templates de servicios, asi como su intervalo y sus periodos
cfg_dir=/etc/nagios/objects/Templates.cfg

En /ect/nagios/conf.d definiremos en primer lugar los host y sus grupos
Crearemos un archivo .cfg por ejemplo nag.cfg lo editaremos y cargaremos todos los servidores a chequear.

Creación de host

define host{
use windows-server #es el template a utilizar definido en Template.cfg
hostname servidor1
alias My windows server
addrees 192.168.1.5 
}
Define host{
use windows-server #es el template a utilizar definido en Template.cfg
hostname servidor2
alias My windows server
addrees 192.168.1.6 
}
define host{
use windows-server #es el template a utilizar definido en Template.cfg
hostname exchange1
alias My windows server
addrees 192.168.1.7 
}
Define host{
use windows-server #es el template a utilizar definido en Template.cfg
hostname exchange2
alias My windows server
addrees 192.168.1.8
}


Difiniendo Hostgroups

define hostgroup{
hostgroup_name windows-servers
alias Windows Servers
members server1, server2
}
define hostgroup{
hostgroup_name exchange-servers
alias Exchange Servers
members exchange1, exchanger2
}

Definimos en /etc/nagios/objects/windows.cfg los servicios a chequear en cada host

Por ejemplo para chequear el disco c:\ de los servidores windows deberiamos definirlo de la siguiente manera
define service{
	use			generic-service
	host_name		servidor1, servidor2
	service_description	C:\Drives Space
	check_command		check_nt!USEDDISKSPACE!-p 12489 -l c -w 80 -c 90
	}

Donde 
use      generis service es el template a utilizar
host_name   servidor1, servidor2 son los servidores a chequear
service_description  C:\Drive Space es el nombre que recibira el servicio
check_command check_nt!USEDDISKSPACE!-p 12489 –l c –w 80 –c 90

check_nt es el pluguin a utilizar, USEDDISKSPACE es el comando que ejecutaremos –p 12489 es 
el puerto por el cual nos conectaremos al cliente instalado en el servidor –l c le indicamos 
que disco deseamos que revise –w 80 y –c 90 indican la importancia de los warings en el caso 
del –w y la importacia de los criticals en el caso de los –c.

Para chequear la memoria en uso de los exchange server por ejemplo usaremos

define service{
	use			generic-service
	host_name		exchange1, echange2
	service_description	Memory Usage
	check_command		check_nt!MEMUSE!-w 80 -c 90


Si queremos chequear un servidor web lo haremos de la siguiente manera

define service{
	use			generic-service
	host_name		servidor2
	service_description	myweb
	check_command		check_http!-I 198.162.1.6 -u http://myweb.com/index.html
	}

Agregando Comandos
En Nagios los encargados de recabar los datos del monitoreo, de mostrar alertas, de todas las tareas, son los comandos.
Los mismos se dividen en comandos de performance y en comandos de chequeo, los primeros son utilizados para algunos casos en particular.
Los comandos de chequeo no traen datos de los equipos a monitorear, como consumo de CPU, Memoria, Disco, procesos corriendo, puertos abiertos etc, es decir todos los datos necesarios para el monitoreo.
Los comandos de performance se utilizan cuando hay que guardar ciertos datos o enviarlos a algún host externo etc, con información de algún servicio.
Una entrada en un archivo de configuración de comandos puede ser como la siguiente

define command{
command_name check_snmp_mem
command_line $USER1$/check_snmp_mem.pl -H $HOSTADDRESS$ $ARG1$ -w $ARG2$ -c $ARG3$ $ARG4$
}
define command{
command_name {nombre del comando}
command_line {datos de ejecucion}
}
command_name

El nombre que el comando tendra para nuestra configuración personal de Nagios
command_line
Modo del cual Nagios ejecutara el comando en cuestión, con su ruta física y argumentos Lo que vemos en entre signos $ son variables internas de nagios, llamadas macros, las mas comunes son:

$USER1$ : Contiene datos del path de ejecución de los plugins de Nagios
$HOSTADDRESS$ : Tiene la IP de hosts desde el cual se esta corriendo el servicio
$ARG1$ $ARG2$ $ARG3$ $ARG4$ : Son los números en orden de argumentos que recibe el comando a ejecutar

Podemos definir nuestros propios macros seteando variables en el archivo resource.cfg
Se deberán agregar al archivo {nagiosdir}/etc/nagios/objects/commands.cfg las entradas correspondientes anteriormente explicadas.

Y por ultimo tenemos Templates.cfg donde configuraremos los templates utilizados en los archivos anteriores.

Por ejemplo los templates para los host quedarian de la siguiente forma
define host{
	name	windows-server	; The name of this host template
	use	generic-host	; Inherit default values from the generic-host template
	check_period	24x7	; By default, Windows servers are monitored round the clock
	check_interval		1 ; Actively check the server every 5 minutes
	retry_interval		1	; Schedule host check retries at 1 minute intervals
	max_check_attempts	10	; Check each server 10 times (max)
	check_command	check-host-alive ; Default command to check if servers are "alive"
	notification_period	24x7	; Send notification out at any time - day or night
	notification_interval	1		; Resend notifications every 30 minutes
	notification_options	d,r		; Only send notifications for specific host states
	contact_groups		admins		; Notifications get sent to the admins by default
	hostgroups	windows-servers ; Host groups that Windows servers should be a member of
	register		0	; DONT REGISTER THIS - ITS JUST A TEMPLATE
	}

# Windows host definition template - This is NOT a real host, just a template!

define host{
	name		exchange-server	; The name of this host template
	use		generic-host	; Inherit default values from the generic-host template
	check_period		24x7	; By default, Windows servers are monitored round the clock
	check_interval		1		; Actively check the server every 5 minutes
	retry_interval		1		; Schedule host check retries at 1 minute intervals
	max_check_attempts	10		; Check each server 10 times (max)
	check_command		check-host-alive	; Default command to check if servers are "alive"
	notification_period	24x7		; Send notification out at any time - day or night
	notification_interval	1		; Resend notifications every 30 minutes
	notification_options	d,r		; Only send notifications for specific host states
	contact_groups		admins		; Notifications get sent to the admins by default
	hostgroups	exchange-servers ; Host groups that Windows servers should be a member of
	register		0		; DONT REGISTER THIS - ITS JUST A TEMPLATE
	}

Los templates de servicios quedarian de la siguiente forma

# Generic service definition template - This is NOT a real service, just a template!

define service{
        name                   generic-service       ; The 'name' of this service template
        active_checks_enabled           1       	; Active service checks are enabled
        passive_checks_enabled        1         ; Passive service checks are enabled/accepted
        parallelize_check               1     ; Active service checks should be parallelized (disabling #this can lead to major performance problems)
        obsess_over_service             1       	; We should obsess over this service (if necessary)
        check_freshness                 0       	; Default is to NOT check service 'freshness'
        notifications_enabled           1       	; Service notifications are enabled
        event_handler_enabled           1       	; Service event handler is enabled
        flap_detection_enabled          1       	; Flap detection is enabled
        failure_prediction_enabled      1       	; Failure prediction is enabled
        process_perf_data               1       	; Process performance data
        retain_status_information       1       	; Retain status information across program restarts
        retain_nonstatus_information    1       ; Retain non-status information across program restarts
        is_volatile                     0       	; The service is not volatile
        check_period                    24x7	; The service can be checked at any time of the day
        max_check_attempts      3   ; Re-check the service up to 3 times in order to determine
 #its final (hard) state
        normal_check_interval           1 ; Check the service every 1 minutes under normal conditions
        retry_check_interval            1	; Re-check the service every one minutes until a hard state
 #can be determined
        contact_groups                  admins; Notifications get sent out to everyone in the 'admins' group
         notification_options   w,u,c,r	; Send notifications about warning, unknown, critical, and #recovery events
        notification_interval           60	 ; Re-notify about service problems every hour
        notification_period             24x7 ; Notifications can be sent out at any time
         register                        0       ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, #JUST A TEMPLATE!
        }

Por ultimo tendremos que configurar el archivo /etc/nagios/nagios.cfg para habilitar los archivos que utilizaremos.

De tal manera que nos quede de la siguiente forma:
##############################################################################
#
# NAGIOS.CFG - Sample Main Config File for Nagios 3.0.2
#
# Read the documentation for more information on this configuration
# file.  I've provided some comments here, but things may not be so
# clear without further explanation.
#
# Last Modified: 05-19-2008
#
##############################################################################


# LOG FILE
# This is the main log file where service and host events are logged
# for historical purposes.  This should be the first option specified 
# in the config file!!!

log_file=/var/log/nagios/nagios.log

# load command definitions for plugins
#cfg_dir=/etc/nagios/plugins.d

# OBJECT CONFIGURATION FILE(S)
# These are the object configuration files in which you define hosts,
# host groups, contacts, contact groups, services, etc.
# You can split your object definitions across several config files
# if you wish (as shown below), or keep them all in a single config file.

# You can specify individual object config files as shown below:
cfg_file=/etc/nagios/objects/commands.cfg
cfg_file=/etc/nagios/objects/contacts.cfg
cfg_file=/etc/nagios/objects/timeperiods.cfg
cfg_file=/etc/nagios/objects/templates.cfg

# Definitions for monitoring the local (Linux) host
#cfg_file=/etc/nagios/objects/localhost.cfg

# Definitions for monitoring a Windows machine
cfg_file=/etc/nagios/objects/windows.cfg

# Definitions for monitoring a router/switch
#cfg_file=/etc/nagios/objects/switch.cfg

# Definitions for monitoring a network printer
#cfg_file=/etc/nagios/objects/printer.cfg

# load configuration files on the fly
cfg_dir=/etc/nagios/conf.d

# You can also tell Nagios to process all config files (with a .cfg
# extension) in a particular directory by using the cfg_dir
# directive as shown below:

cfg_dir=/etc/nagios/servers
cfg_dir=/etc/nagios/printers
cfg_dir=/etc/nagios/switches
cfg_dir=/etc/nagios/routers


# OBJECT CACHE FILE
# This option determines where object definitions are cached when
# Nagios starts/restarts.  The CGIs read object definitions from 
# this cache file (rather than looking at the object config files
# directly) in order to prevent inconsistencies that can occur
# when the config files are modified after Nagios starts.

object_cache_file=/var/log/nagios/objects.cache



# PRE-CACHED OBJECT FILE
# This options determines the location of the precached object file.
# If you run Nagios with the -p command line option, it will preprocess
# your object configuration file(s) and write the cached config to this
# file.  You can then start Nagios with the -u option to have it read
# object definitions from this precached file, rather than the standard
# object configuration files (see the cfg_file and cfg_dir options above).
# Using a precached object file can speed up the time needed to (re)start 
# the Nagios process if you've got a large and/or complex configuration.
# Read the documentation section on optimizing Nagios to find our more
# about how this feature works.

precached_object_file=/var/log/nagios/objects.precache



# RESOURCE FILE
# This is an optional resource file that contains $USERx$ macro
# definitions. Multiple resource files can be specified by using
# multiple resource_file definitions.  The CGIs will not attempt to
# read the contents of resource files, so information that is
# considered to be sensitive (usernames, passwords, etc) can be
# defined as macros in this file and restrictive permissions (600)
# can be placed on this file.

resource_file=/etc/nagios/resource.cfg



# STATUS FILE
# This is where the current status of all monitored services and
# hosts is stored.  Its contents are read and processed by the CGIs.
# The contents of the status file are deleted every time Nagios
#  restarts.

status_file=/var/log/nagios/status.dat



# STATUS FILE UPDATE INTERVAL
# This option determines the frequency (in seconds) that
# Nagios will periodically dump program, host, and 
# service status data.

status_update_interval=10



# NAGIOS USER
# This determines the effective user that Nagios should run as.  
# You can either supply a username or a UID.

nagios_user=nagios



# NAGIOS GROUP
# This determines the effective group that Nagios should run as.  
# You can either supply a group name or a GID.

nagios_group=nagios



# EXTERNAL COMMAND OPTION
# This option allows you to specify whether or not Nagios should check
# for external commands (in the command file defined below).  By default
# Nagios will *not* check for external commands, just to be on the
# cautious side.  If you want to be able to use the CGI command interface
# you will have to enable this.
# Values: 0 = disable commands, 1 = enable commands

check_external_commands=1



# EXTERNAL COMMAND CHECK INTERVAL
# This is the interval at which Nagios should check for external commands.
# This value works of the interval_length you specify later.  If you leave
# that at its default value of 60 (seconds), a value of 1 here will cause
# Nagios to check for external commands every minute.  If you specify a
# number followed by an "s" (i.e. 15s), this will be interpreted to mean
# actual seconds rather than a multiple of the interval_length variable.
# Note: In addition to reading the external command file at regularly 
# scheduled intervals, Nagios will also check for external commands after
# event handlers are executed.
# NOTE: Setting this value to -1 causes Nagios to check the external
# command file as often as possible.

#command_check_interval=15s
command_check_interval=-1



# EXTERNAL COMMAND FILE
# This is the file that Nagios checks for external command requests.
# It is also where the command CGI will write commands that are submitted
# by users, so it must be writeable by the user that the web server
# is running as (usually 'nobody').  Permissions should be set at the 
# directory level instead of on the file, as the file is deleted every
# time its contents are processed.

command_file=/var/spool/nagios/nagios.cmd



# EXTERNAL COMMAND BUFFER SLOTS
# This settings is used to tweak the number of items or "slots" that
# the Nagios daemon should allocate to the buffer that holds incoming 
# external commands before they are processed.  As external commands 
# are processed by the daemon, they are removed from the buffer.  

external_command_buffer_slots=4096



# LOCK FILE
# This is the lockfile that Nagios will use to store its PID number
# in when it is running in daemon mode.

lock_file=/var/run/nagios/nagios.pid



# TEMP FILE
# This is a temporary file that is used as scratch space when Nagios
# updates the status log, cleans the comment file, etc.  This file
# is created, used, and deleted throughout the time that Nagios is
# running.

temp_file=/var/log/nagios/nagios.tmp



# TEMP PATH
# This is path where Nagios can create temp files for service and
# host check results, etc.

temp_path=/tmp



# EVENT BROKER OPTIONS
# Controls what (if any) data gets sent to the event broker.
# Values:  0      = Broker nothing
#         -1      = Broker everything
#          = See documentation

event_broker_options=-1



# EVENT BROKER MODULE(S)
# This directive is used to specify an event broker module that should
# by loaded by Nagios at startup.  Use multiple directives if you want
# to load more than one module.  Arguments that should be passed to
# the module at startup are seperated from the module path by a space.
#
#!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
# WARNING !!! WARNING !!! WARNING !!! WARNING !!! WARNING !!! WARNING
#!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#
# Do NOT overwrite modules while they are being used by Nagios or Nagios
# will crash in a fiery display of SEGFAULT glory.  This is a bug/limitation
# either in dlopen(), the kernel, and/or the filesystem.  And maybe Nagios...
#
# The correct/safe way of updating a module is by using one of these methods:
#    1. Shutdown Nagios, replace the module file, restart Nagios
#    2. Delete the original module file, move the new module file into place, restart Nagios
#
# Example:
#
#   broker_module= [moduleargs]

#broker_module=/somewhere/module1.o
#broker_module=/somewhere/module2.o arg1 arg2=3 debug=0



# LOG ROTATION METHOD
# This is the log rotation method that Nagios should use to rotate
# the main log file. Values are as follows..
#	n	= None - don't rotate the log
#	h	= Hourly rotation (top of the hour)
#	d	= Daily rotation (midnight every day)
#	w	= Weekly rotation (midnight on Saturday evening)
#	m	= Monthly rotation (midnight last day of month)

log_rotation_method=d



# LOG ARCHIVE PATH
# This is the directory where archived (rotated) log files should be 
# placed (assuming you've chosen to do log rotation).

log_archive_path=/var/log/nagios/archives



# LOGGING OPTIONS
# If you want messages logged to the syslog facility, as well as the
# Nagios log file set this option to 1.  If not, set it to 0.

use_syslog=1



# NOTIFICATION LOGGING OPTION
# If you don't want notifications to be logged, set this value to 0.
# If notifications should be logged, set the value to 1.

log_notifications=1



# SERVICE RETRY LOGGING OPTION
# If you don't want service check retries to be logged, set this value
# to 0.  If retries should be logged, set the value to 1.

log_service_retries=1



# HOST RETRY LOGGING OPTION
# If you don't want host check retries to be logged, set this value to
# 0.  If retries should be logged, set the value to 1.

log_host_retries=1



# EVENT HANDLER LOGGING OPTION
# If you don't want host and service event handlers to be logged, set
# this value to 0.  If event handlers should be logged, set the value
# to 1.

log_event_handlers=1



# INITIAL STATES LOGGING OPTION
# If you want Nagios to log all initial host and service states to
# the main log file (the first time the service or host is checked)
# you can enable this option by setting this value to 1.  If you
# are not using an external application that does long term state
# statistics reporting, you do not need to enable this option.  In
# this case, set the value to 0.

log_initial_states=0



# EXTERNAL COMMANDS LOGGING OPTION
# If you don't want Nagios to log external commands, set this value
# to 0.  If external commands should be logged, set this value to 1.
# Note: This option does not include logging of passive service
# checks - see the option below for controlling whether or not
# passive checks are logged.

log_external_commands=1



# PASSIVE CHECKS LOGGING OPTION
# If you don't want Nagios to log passive host and service checks, set
# this value to 0.  If passive checks should be logged, set
# this value to 1.

log_passive_checks=1



# GLOBAL HOST AND SERVICE EVENT HANDLERS
# These options allow you to specify a host and service event handler
# command that is to be run for every host or service state change.
# The global event handler is executed immediately prior to the event
# handler that you have optionally specified in each host or
# service definition. The command argument is the short name of a
# command definition that you define in your host configuration file.
# Read the HTML docs for more information.

#global_host_event_handler=somecommand
#global_service_event_handler=somecommand



# SERVICE INTER-CHECK DELAY METHOD
# This is the method that Nagios should use when initially
# "spreading out" service checks when it starts monitoring.  The
# default is to use smart delay calculation, which will try to
# space all service checks out evenly to minimize CPU load.
# Using the dumb setting will cause all checks to be scheduled
# at the same time (with no delay between them)!  This is not a
# good thing for production, but is useful when testing the
# parallelization functionality.
#	n	= None - don't use any delay between checks
#	d	= Use a "dumb" delay of 1 second between checks
#	s	= Use "smart" inter-check delay calculation
#       x.xx    = Use an inter-check delay of x.xx seconds

service_inter_check_delay_method=s



# MAXIMUM SERVICE CHECK SPREAD
# This variable determines the timeframe (in minutes) from the
# program start time that an initial check of all services should
# be completed.  Default is 30 minutes.

max_service_check_spread=30



# SERVICE CHECK INTERLEAVE FACTOR
# This variable determines how service checks are interleaved.
# Interleaving the service checks allows for a more even
# distribution of service checks and reduced load on remote
# hosts.  Setting this value to 1 is equivalent to how versions
# of Nagios previous to 0.0.5 did service checks.  Set this
# value to s (smart) for automatic calculation of the interleave
# factor unless you have a specific reason to change it.
#       s       = Use "smart" interleave factor calculation
#       x       = Use an interleave factor of x, where x is a
#                 number greater than or equal to 1.

service_interleave_factor=s



# HOST INTER-CHECK DELAY METHOD
# This is the method that Nagios should use when initially
# "spreading out" host checks when it starts monitoring.  The
# default is to use smart delay calculation, which will try to
# space all host checks out evenly to minimize CPU load.
# Using the dumb setting will cause all checks to be scheduled
# at the same time (with no delay between them)!
#	n	= None - don't use any delay between checks
#	d	= Use a "dumb" delay of 1 second between checks
#	s	= Use "smart" inter-check delay calculation
#       x.xx    = Use an inter-check delay of x.xx seconds

host_inter_check_delay_method=s



# MAXIMUM HOST CHECK SPREAD
# This variable determines the timeframe (in minutes) from the
# program start time that an initial check of all hosts should
# be completed.  Default is 30 minutes.

max_host_check_spread=30



# MAXIMUM CONCURRENT SERVICE CHECKS
# This option allows you to specify the maximum number of 
# service checks that can be run in parallel at any given time.
# Specifying a value of 1 for this variable essentially prevents
# any service checks from being parallelized.  A value of 0
# will not restrict the number of concurrent checks that are
# being executed.

max_concurrent_checks=0



# HOST AND SERVICE CHECK REAPER FREQUENCY
# This is the frequency (in seconds!) that Nagios will process
# the results of host and service checks.

check_result_reaper_frequency=10




# MAX CHECK RESULT REAPER TIME
# This is the max amount of time (in seconds) that  a single
# check result reaper event will be allowed to run before 
# returning control back to Nagios so it can perform other
# duties.

max_check_result_reaper_time=30




# CHECK RESULT PATH
# This is directory where Nagios stores the results of host and
# service checks that have not yet been processed.
#
# Note: Make sure that only one instance of Nagios has access
# to this directory!  

check_result_path=/var/spool/nagios/checkresults




# MAX CHECK RESULT FILE AGE
# This option determines the maximum age (in seconds) which check
# result files are considered to be valid.  Files older than this 
# threshold will be mercilessly deleted without further processing.

max_check_result_file_age=3600




# CACHED HOST CHECK HORIZON
# This option determines the maximum amount of time (in seconds)
# that the state of a previous host check is considered current.
# Cached host states (from host checks that were performed more
# recently that the timeframe specified by this value) can immensely
# improve performance in regards to the host check logic.
# Too high of a value for this option may result in inaccurate host
# states being used by Nagios, while a lower value may result in a
# performance hit for host checks.  Use a value of 0 to disable host
# check caching.

cached_host_check_horizon=15



# CACHED SERVICE CHECK HORIZON
# This option determines the maximum amount of time (in seconds)
# that the state of a previous service check is considered current.
# Cached service states (from service checks that were performed more
# recently that the timeframe specified by this value) can immensely
# improve performance in regards to predictive dependency checks.
# Use a value of 0 to disable service check caching.

cached_service_check_horizon=15



# ENABLE PREDICTIVE HOST DEPENDENCY CHECKS
# This option determines whether or not Nagios will attempt to execute
# checks of hosts when it predicts that future dependency logic test
# may be needed.  These predictive checks can help ensure that your
# host dependency logic works well.
# Values:
#  0 = Disable predictive checks
#  1 = Enable predictive checks (default)

enable_predictive_host_dependency_checks=1



# ENABLE PREDICTIVE SERVICE DEPENDENCY CHECKS
# This option determines whether or not Nagios will attempt to execute
# checks of service when it predicts that future dependency logic test
# may be needed.  These predictive checks can help ensure that your
# service dependency logic works well.
# Values:
#  0 = Disable predictive checks
#  1 = Enable predictive checks (default)

enable_predictive_service_dependency_checks=1



# SOFT STATE DEPENDENCIES
# This option determines whether or not Nagios will use soft state 
# information when checking host and service dependencies. Normally 
# Nagios will only use the latest hard host or service state when 
# checking dependencies. If you want it to use the latest state (regardless
# of whether its a soft or hard state type), enable this option. 
# Values:
#  0 = Don't use soft state dependencies (default) 
#  1 = Use soft state dependencies 

soft_state_dependencies=0



# AUTO-RESCHEDULING OPTION
# This option determines whether or not Nagios will attempt to
# automatically reschedule active host and service checks to
# "smooth" them out over time.  This can help balance the load on
# the monitoring server.  
# WARNING: THIS IS AN EXPERIMENTAL FEATURE - IT CAN DEGRADE
# PERFORMANCE, RATHER THAN INCREASE IT, IF USED IMPROPERLY

auto_reschedule_checks=0



# AUTO-RESCHEDULING INTERVAL
# This option determines how often (in seconds) Nagios will
# attempt to automatically reschedule checks.  This option only
# has an effect if the auto_reschedule_checks option is enabled.
# Default is 30 seconds.
# WARNING: THIS IS AN EXPERIMENTAL FEATURE - IT CAN DEGRADE
# PERFORMANCE, RATHER THAN INCREASE IT, IF USED IMPROPERLY

auto_rescheduling_interval=30



# AUTO-RESCHEDULING WINDOW
# This option determines the "window" of time (in seconds) that
# Nagios will look at when automatically rescheduling checks.
# Only host and service checks that occur in the next X seconds
# (determined by this variable) will be rescheduled. This option
# only has an effect if the auto_reschedule_checks option is
# enabled.  Default is 180 seconds (3 minutes).
# WARNING: THIS IS AN EXPERIMENTAL FEATURE - IT CAN DEGRADE
# PERFORMANCE, RATHER THAN INCREASE IT, IF USED IMPROPERLY

auto_rescheduling_window=180



# SLEEP TIME
# This is the number of seconds to sleep between checking for system
# events and service checks that need to be run.

sleep_time=0.25



# TIMEOUT VALUES
# These options control how much time Nagios will allow various
# types of commands to execute before killing them off.  Options
# are available for controlling maximum time allotted for
# service checks, host checks, event handlers, notifications, the
# ocsp command, and performance data commands.  All values are in
# seconds.

service_check_timeout=60
host_check_timeout=30
event_handler_timeout=30
notification_timeout=30
ocsp_timeout=5
perfdata_timeout=5



# RETAIN STATE INFORMATION
# This setting determines whether or not Nagios will save state
# information for services and hosts before it shuts down.  Upon
# startup Nagios will reload all saved service and host state
# information before starting to monitor.  This is useful for 
# maintaining long-term data on state statistics, etc, but will
# slow Nagios down a bit when it (re)starts.  Since its only
# a one-time penalty, I think its well worth the additional
# startup delay.

retain_state_information=1



# STATE RETENTION FILE
# This is the file that Nagios should use to store host and
# service state information before it shuts down.  The state 
# information in this file is also read immediately prior to
# starting to monitor the network when Nagios is restarted.
# This file is used only if the preserve_state_information
# variable is set to 1.

state_retention_file=/var/log/nagios/retention.dat



# RETENTION DATA UPDATE INTERVAL
# This setting determines how often (in minutes) that Nagios
# will automatically save retention data during normal operation.
# If you set this value to 0, Nagios will not save retention
# data at regular interval, but it will still save retention
# data before shutting down or restarting.  If you have disabled
# state retention, this option has no effect.

retention_update_interval=60



# USE RETAINED PROGRAM STATE
# This setting determines whether or not Nagios will set 
# program status variables based on the values saved in the
# retention file.  If you want to use retained program status
# information, set this value to 1.  If not, set this value
# to 0.

use_retained_program_state=1



# USE RETAINED SCHEDULING INFO
# This setting determines whether or not Nagios will retain
# the scheduling info (next check time) for hosts and services
# based on the values saved in the retention file.  If you
# If you want to use retained scheduling info, set this
# value to 1.  If not, set this value to 0.

use_retained_scheduling_info=1



# RETAINED ATTRIBUTE MASKS (ADVANCED FEATURE)
# The following variables are used to specify specific host and
# service attributes that should *not* be retained by Nagios during
# program restarts.
#
# The values of the masks are bitwise ANDs of values specified
# by the "MODATTR_" definitions found in include/common.h.  
# For example, if you do not want the current enabled/disabled state
# of flap detection and event handlers for hosts to be retained, you
# would use a value of 24 for the host attribute mask...
# MODATTR_EVENT_HANDLER_ENABLED (8) + MODATTR_FLAP_DETECTION_ENABLED (16) = 24

# This mask determines what host attributes are not retained
retained_host_attribute_mask=0

# This mask determines what service attributes are not retained
retained_service_attribute_mask=0

# These two masks determine what process attributes are not retained.
# There are two masks, because some process attributes have host and service
# options.  For example, you can disable active host checks, but leave active
# service checks enabled.
retained_process_host_attribute_mask=0
retained_process_service_attribute_mask=0

# These two masks determine what contact attributes are not retained.
# There are two masks, because some contact attributes have host and
# service options.  For example, you can disable host notifications for
# a contact, but leave service notifications enabled for them.
retained_contact_host_attribute_mask=0
retained_contact_service_attribute_mask=0



# INTERVAL LENGTH
# This is the seconds per unit interval as used in the
# host/contact/service configuration files.  Setting this to 60 means
# that each interval is one minute long (60 seconds).  Other settings
# have not been tested much, so your mileage is likely to vary...

interval_length=60



# AGGRESSIVE HOST CHECKING OPTION
# If you don't want to turn on aggressive host checking features, set
# this value to 0 (the default).  Otherwise set this value to 1 to
# enable the aggressive check option.  Read the docs for more info
# on what aggressive host check is or check out the source code in
# base/checks.c

use_aggressive_host_checking=0



# SERVICE CHECK EXECUTION OPTION
# This determines whether or not Nagios will actively execute
# service checks when it initially starts.  If this option is 
# disabled, checks are not actively made, but Nagios can still
# receive and process passive check results that come in.  Unless
# you're implementing redundant hosts or have a special need for
# disabling the execution of service checks, leave this enabled!
# Values: 1 = enable checks, 0 = disable checks

execute_service_checks=1



# PASSIVE SERVICE CHECK ACCEPTANCE OPTION
# This determines whether or not Nagios will accept passive
# service checks results when it initially (re)starts.
# Values: 1 = accept passive checks, 0 = reject passive checks

accept_passive_service_checks=1



# HOST CHECK EXECUTION OPTION
# This determines whether or not Nagios will actively execute
# host checks when it initially starts.  If this option is 
# disabled, checks are not actively made, but Nagios can still
# receive and process passive check results that come in.  Unless
# you're implementing redundant hosts or have a special need for
# disabling the execution of host checks, leave this enabled!
# Values: 1 = enable checks, 0 = disable checks

execute_host_checks=1



# PASSIVE HOST CHECK ACCEPTANCE OPTION
# This determines whether or not Nagios will accept passive
# host checks results when it initially (re)starts.
# Values: 1 = accept passive checks, 0 = reject passive checks

accept_passive_host_checks=1



# NOTIFICATIONS OPTION
# This determines whether or not Nagios will sent out any host or
# service notifications when it is initially (re)started.
# Values: 1 = enable notifications, 0 = disable notifications

enable_notifications=1



# EVENT HANDLER USE OPTION
# This determines whether or not Nagios will run any host or
# service event handlers when it is initially (re)started.  Unless
# you're implementing redundant hosts, leave this option enabled.
# Values: 1 = enable event handlers, 0 = disable event handlers

enable_event_handlers=1



# PROCESS PERFORMANCE DATA OPTION
# This determines whether or not Nagios will process performance
# data returned from service and host checks.  If this option is
# enabled, host performance data will be processed using the
# host_perfdata_command (defined below) and service performance
# data will be processed using the service_perfdata_command (also
# defined below).  Read the HTML docs for more information on
# performance data.
# Values: 1 = process performance data, 0 = do not process performance data

process_performance_data=0



# HOST AND SERVICE PERFORMANCE DATA PROCESSING COMMANDS
# These commands are run after every host and service check is
# performed.  These commands are executed only if the
# enable_performance_data option (above) is set to 1.  The command
# argument is the short name of a command definition that you 
# define in your host configuration file.  Read the HTML docs for
# more information on performance data.

#host_perfdata_command=process-host-perfdata
#service_perfdata_command=process-service-perfdata



# HOST AND SERVICE PERFORMANCE DATA FILES
# These files are used to store host and service performance data.
# Performance data is only written to these files if the
# enable_performance_data option (above) is set to 1.

#host_perfdata_file=/tmp/host-perfdata
#service_perfdata_file=/tmp/service-perfdata



# HOST AND SERVICE PERFORMANCE DATA FILE TEMPLATES
# These options determine what data is written (and how) to the
# performance data files.  The templates may contain macros, special
# characters (\t for tab, \r for carriage return, \n for newline)
# and plain text.  A newline is automatically added after each write
# to the performance data file.  Some examples of what you can do are
# shown below.

#host_perfdata_file_template=[HOSTPERFDATA]\t$TIMET$\t$HOSTNAME$\t$HOSTEXECUTIONTIME$\t$HOSTOUTPUT$\t$HOSTPERFDATA$
#service_perfdata_file_template=[SERVICEPERFDATA]\t$TIMET$\t$HOSTNAME$\t$SERVICEDESC$\t$SERVICEEXECUTIONTIME$\t$SERVICELATENCY$\t$SERVICEOUTPUT$\t$SERVICEPERFDATA$



# HOST AND SERVICE PERFORMANCE DATA FILE MODES
# This option determines whether or not the host and service
# performance data files are opened in write ("w") or append ("a")
# mode. If you want to use named pipes, you should use the special
# pipe ("p") mode which avoid blocking at startup, otherwise you will
# likely want the defult append ("a") mode.

#host_perfdata_file_mode=a
#service_perfdata_file_mode=a



# HOST AND SERVICE PERFORMANCE DATA FILE PROCESSING INTERVAL
# These options determine how often (in seconds) the host and service
# performance data files are processed using the commands defined
# below.  A value of 0 indicates the files should not be periodically
# processed.

#host_perfdata_file_processing_interval=0
#service_perfdata_file_processing_interval=0



# HOST AND SERVICE PERFORMANCE DATA FILE PROCESSING COMMANDS
# These commands are used to periodically process the host and
# service performance data files.  The interval at which the
# processing occurs is determined by the options above.

#host_perfdata_file_processing_command=process-host-perfdata-file
#service_perfdata_file_processing_command=process-service-perfdata-file



# OBSESS OVER SERVICE CHECKS OPTION
# This determines whether or not Nagios will obsess over service
# checks and run the ocsp_command defined below.  Unless you're
# planning on implementing distributed monitoring, do not enable
# this option.  Read the HTML docs for more information on
# implementing distributed monitoring.
# Values: 1 = obsess over services, 0 = do not obsess (default)

obsess_over_services=0



# OBSESSIVE COMPULSIVE SERVICE PROCESSOR COMMAND
# This is the command that is run for every service check that is
# processed by Nagios.  This command is executed only if the
# obsess_over_services option (above) is set to 1.  The command 
# argument is the short name of a command definition that you
# define in your host configuration file. Read the HTML docs for
# more information on implementing distributed monitoring.

#ocsp_command=somecommand



# OBSESS OVER HOST CHECKS OPTION
# This determines whether or not Nagios will obsess over host
# checks and run the ochp_command defined below.  Unless you're
# planning on implementing distributed monitoring, do not enable
# this option.  Read the HTML docs for more information on
# implementing distributed monitoring.
# Values: 1 = obsess over hosts, 0 = do not obsess (default)

obsess_over_hosts=0



# OBSESSIVE COMPULSIVE HOST PROCESSOR COMMAND
# This is the command that is run for every host check that is
# processed by Nagios.  This command is executed only if the
# obsess_over_hosts option (above) is set to 1.  The command 
# argument is the short name of a command definition that you
# define in your host configuration file. Read the HTML docs for
# more information on implementing distributed monitoring.

#ochp_command=somecommand



# TRANSLATE PASSIVE HOST CHECKS OPTION
# This determines whether or not Nagios will translate
# DOWN/UNREACHABLE passive host check results into their proper
# state for this instance of Nagios.  This option is useful
# if you have distributed or failover monitoring setup.  In
# these cases your other Nagios servers probably have a different
# "view" of the network, with regards to the parent/child relationship
# of hosts.  If a distributed monitoring server thinks a host
# is DOWN, it may actually be UNREACHABLE from the point of
# this Nagios instance.  Enabling this option will tell Nagios
# to translate any DOWN or UNREACHABLE host states it receives
# passively into the correct state from the view of this server.
# Values: 1 = perform translation, 0 = do not translate (default)

translate_passive_host_checks=0



# PASSIVE HOST CHECKS ARE SOFT OPTION
# This determines whether or not Nagios will treat passive host
# checks as being HARD or SOFT.  By default, a passive host check
# result will put a host into a HARD state type.  This can be changed
# by enabling this option.
# Values: 0 = passive checks are HARD, 1 = passive checks are SOFT

passive_host_checks_are_soft=0



# ORPHANED HOST/SERVICE CHECK OPTIONS
# These options determine whether or not Nagios will periodically 
# check for orphaned host service checks.  Since service checks are
# not rescheduled until the results of their previous execution 
# instance are processed, there exists a possibility that some
# checks may never get rescheduled.  A similar situation exists for
# host checks, although the exact scheduling details differ a bit
# from service checks.  Orphaned checks seem to be a rare
# problem and should not happen under normal circumstances.
# If you have problems with service checks never getting
# rescheduled, make sure you have orphaned service checks enabled.
# Values: 1 = enable checks, 0 = disable checks

check_for_orphaned_services=1
check_for_orphaned_hosts=1



# SERVICE FRESHNESS CHECK OPTION
# This option determines whether or not Nagios will periodically
# check the "freshness" of service results.  Enabling this option
# is useful for ensuring passive checks are received in a timely
# manner.
# Values: 1 = enabled freshness checking, 0 = disable freshness checking

check_service_freshness=1



# SERVICE FRESHNESS CHECK INTERVAL
# This setting determines how often (in seconds) Nagios will
# check the "freshness" of service check results.  If you have
# disabled service freshness checking, this option has no effect.

service_freshness_check_interval=60



# HOST FRESHNESS CHECK OPTION
# This option determines whether or not Nagios will periodically
# check the "freshness" of host results.  Enabling this option
# is useful for ensuring passive checks are received in a timely
# manner.
# Values: 1 = enabled freshness checking, 0 = disable freshness checking

check_host_freshness=0



# HOST FRESHNESS CHECK INTERVAL
# This setting determines how often (in seconds) Nagios will
# check the "freshness" of host check results.  If you have
# disabled host freshness checking, this option has no effect.

host_freshness_check_interval=60




# ADDITIONAL FRESHNESS THRESHOLD LATENCY
# This setting determines the number of seconds that Nagios
# will add to any host and service freshness thresholds that
# it calculates (those not explicitly specified by the user).

additional_freshness_latency=15




# FLAP DETECTION OPTION
# This option determines whether or not Nagios will try
# and detect hosts and services that are "flapping".  
# Flapping occurs when a host or service changes between
# states too frequently.  When Nagios detects that a 
# host or service is flapping, it will temporarily suppress
# notifications for that host/service until it stops
# flapping.  Flap detection is very experimental, so read
# the HTML documentation before enabling this feature!
# Values: 1 = enable flap detection
#         0 = disable flap detection (default)

enable_flap_detection=1



# FLAP DETECTION THRESHOLDS FOR HOSTS AND SERVICES
# Read the HTML documentation on flap detection for
# an explanation of what this option does.  This option
# has no effect if flap detection is disabled.

low_service_flap_threshold=5.0
high_service_flap_threshold=20.0
low_host_flap_threshold=5.0
high_host_flap_threshold=20.0



# DATE FORMAT OPTION
# This option determines how short dates are displayed. Valid options
# include:
#	us		(MM-DD-YYYY HH:MM:SS)
#	euro    	(DD-MM-YYYY HH:MM:SS)
#	iso8601		(YYYY-MM-DD HH:MM:SS)
#	strict-iso8601	(YYYY-MM-DDTHH:MM:SS)
#

date_format=us




# TIMEZONE OFFSET
# This option is used to override the default timezone that this
# instance of Nagios runs in.  If not specified, Nagios will use
# the system configured timezone.
#
# NOTE: In order to display the correct timezone in the CGIs, you
# will also need to alter the Apache directives for the CGI path 
# to include your timezone.  Example:
#
#   
#      SetEnv TZ "Australia/Brisbane"
#      ...
#   

#use_timezone=US/Mountain
#use_timezone=Australia/Brisbane




# P1.PL FILE LOCATION
# This value determines where the p1.pl perl script (used by the
# embedded Perl interpreter) is located.  If you didn't compile
# Nagios with embedded Perl support, this option has no effect.

p1_file=/usr/sbin/p1.pl



# EMBEDDED PERL INTERPRETER OPTION
# This option determines whether or not the embedded Perl interpreter
# will be enabled during runtime.  This option has no effect if Nagios
# has not been compiled with support for embedded Perl.
# Values: 0 = disable interpreter, 1 = enable interpreter

enable_embedded_perl=1



# EMBEDDED PERL USAGE OPTION
# This option determines whether or not Nagios will process Perl plugins
# and scripts with the embedded Perl interpreter if the plugins/scripts
# do not explicitly indicate whether or not it is okay to do so. Read
# the HTML documentation on the embedded Perl interpreter for more 
# information on how this option works.

use_embedded_perl_implicitly=1



# ILLEGAL OBJECT NAME CHARACTERS
# This option allows you to specify illegal characters that cannot
# be used in host names, service descriptions, or names of other
# object types.

illegal_object_name_chars=`~!$%^&*|'"<>?,()=



# ILLEGAL MACRO OUTPUT CHARACTERS
# This option allows you to specify illegal characters that are
# stripped from macros before being used in notifications, event
# handlers, etc.  This DOES NOT affect macros used in service or
# host check commands.
# The following macros are stripped of the characters you specify:
#	$HOSTOUTPUT$
#	$HOSTPERFDATA$
#	$HOSTACKAUTHOR$
#	$HOSTACKCOMMENT$
#	$SERVICEOUTPUT$
#	$SERVICEPERFDATA$
#	$SERVICEACKAUTHOR$
#	$SERVICEACKCOMMENT$

illegal_macro_output_chars=`~$&|'"<>



# REGULAR EXPRESSION MATCHING
# This option controls whether or not regular expression matching
# takes place in the object config files.  Regular expression
# matching is used to match host, hostgroup, service, and service
# group names/descriptions in some fields of various object types.
# Values: 1 = enable regexp matching, 0 = disable regexp matching

use_regexp_matching=0



# "TRUE" REGULAR EXPRESSION MATCHING
# This option controls whether or not "true" regular expression 
# matching takes place in the object config files.  This option
# only has an effect if regular expression matching is enabled
# (see above).  If this option is DISABLED, regular expression
# matching only occurs if a string contains wildcard characters
# (* and ?).  If the option is ENABLED, regexp matching occurs
# all the time (which can be annoying).
# Values: 1 = enable true matching, 0 = disable true matching

use_true_regexp_matching=0



# ADMINISTRATOR EMAIL/PAGER ADDRESSES
# The email and pager address of a global administrator (likely you).
# Nagios never uses these values itself, but you can access them by
# using the $ADMINEMAIL$ and $ADMINPAGER$ macros in your notification
# commands.

admin_email=nagios@localhost
admin_pager=pagenagios@localhost



# DAEMON CORE DUMP OPTION
# This option determines whether or not Nagios is allowed to create
# a core dump when it runs as a daemon.  Note that it is generally
# considered bad form to allow this, but it may be useful for
# debugging purposes.  Enabling this option doesn't guarantee that
# a core file will be produced, but that's just life...
# Values: 1 - Allow core dumps
#         0 - Do not allow core dumps (default)

daemon_dumps_core=0



# LARGE INSTALLATION TWEAKS OPTION
# This option determines whether or not Nagios will take some shortcuts
# which can save on memory and CPU usage in large Nagios installations.
# Read the documentation for more information on the benefits/tradeoffs
# of enabling this option.
# Values: 1 - Enabled tweaks
#         0 - Disable tweaks (default)

use_large_installation_tweaks=0



# ENABLE ENVIRONMENT MACROS
# This option determines whether or not Nagios will make all standard
# macros available as environment variables when host/service checks
# and system commands (event handlers, notifications, etc.) are
# executed.  Enabling this option can cause performance issues in 
# large installations, as it will consume a bit more memory and (more
# importantly) consume more CPU.
# Values: 1 - Enable environment variable macros (default)
#         0 - Disable environment variable macros

enable_environment_macros=1



# CHILD PROCESS MEMORY OPTION
# This option determines whether or not Nagios will free memory in
# child processes (processed used to execute system commands and host/
# service checks).  If you specify a value here, it will override
# program defaults.
# Value: 1 - Free memory in child processes
#        0 - Do not free memory in child processes

#free_child_process_memory=1



# CHILD PROCESS FORKING BEHAVIOR
# This option determines how Nagios will fork child processes
# (used to execute system commands and host/service checks).  Normally
# child processes are fork()ed twice, which provides a very high level
# of isolation from problems.  Fork()ing once is probably enough and will
# save a great deal on CPU usage (in large installs), so you might
# want to consider using this.  If you specify a value here, it will
# program defaults.
# Value: 1 - Child processes fork() twice
#        0 - Child processes fork() just once

#child_processes_fork_twice=1



# DEBUG LEVEL
# This option determines how much (if any) debugging information will
# be written to the debug file.  OR values together to log multiple
# types of information.
# Values: 
#          -1 = Everything
#          0 = Nothing
#	   1 = Functions
#          2 = Configuration
#          4 = Process information
#	   8 = Scheduled events
#          16 = Host/service checks
#          32 = Notifications
#          64 = Event broker
#          128 = External commands
#          256 = Commands
#          512 = Scheduled downtime
#          1024 = Comments
#          2048 = Macros

debug_level=0



# DEBUG VERBOSITY
# This option determines how verbose the debug log out will be.
# Values: 0 = Brief output
#         1 = More detailed
#         2 = Very detailed

debug_verbosity=1



# DEBUG FILE
# This option determines where Nagios should write debugging information.

debug_file=/var/log/nagios/nagios.debug



# MAX DEBUG FILE SIZE
# This option determines the maximum size (in bytes) of the debug file.  If
# the file grows larger than this size, it will be renamed with a .old
# extension.  If a file already exists with a .old extension it will
# automatically be deleted.  This helps ensure your disk space usage doesn't
# get out of control when debugging Nagios.

max_debug_file_size=1000000

Luego en el archivo /etc/nagios/cgi.cfg

Descomentaremos la linea default_user_name=guest y pondremos como usuario a nagios. De tal manera que nos quede de la siguiente forma.

default_user_name=nagios

Una vez realizado iremos a una consola y teclearemos (como usuario root)

service https start

y luego 

service nagios start

Ya tendremos nuestro sistema de monitorización funcionando. Pondremos en nuestro navegador http://ip del servernagios/nagios

Instalación del cliente en maquinas windows

El agente de monitorizacion de nagios se encuentra disponible para las siguientes arquitecturas.
Descargable desde la sieguiente direccion:
http://trac.nakednuns.org/nscp/
una vez descargado y descomprimido en C:\NSCLIENT por consola dentro del directorio donde lo descomprimimos ejecutamos el siguiente comando para instalar el servicio:

C:\NSCLIENT>NSClient++.exe /install

con un editor de texto abrimos el archivo NSC.INI y buscamos las siguientes lineas para habilitar los modulos a usar por nagios.
;FileLogger.dll
;CheckSystem.dll
;CheckDisk.dll
;NSClientListener.dll
;NRPEListener.dll
;SysTray.dll
;CheckEventLog.dll
;CheckHelpers.dll
;CheckWMI.dll
Para descomentarlas solamente debemos eliminar el ";" que tienen delante y el fragmento de texto nos deberia de quedar de la siguiente manera.
;FileLogger.dll
CheckSystem.dll
CheckDisk.dll
NSClientListener.dll
;NRPEListener.dll
;SysTray.dll
CheckEventLog.dll
CheckHelpers.dll
;CheckWMI.dll
;
; RemoteConfiguration IS AN EXTREM EARLY IDEA SO DONT USE FOR PRODUCTION ENVIROMNEMTS!
;RemoteConfiguration.dll
; NSCA Agent is a new beta module use with care!
NSCAAgent.dll
Luego buscamos la lienea que dice:
;allowed_hosts=
esa directiva define el host que puede conectarce o la red a la que se lo permite por ejemplo si solo quisieramos permitir a una maquina que se conecte a nuestro agente la linea deberia de quedar de la siguiente manera:
allowed_hosts=198.162.1.1

Y en la seccion, la dejaremos de la siguiente manera

[NSCA Agent]
;# CHECK INTERVALL (in seconds)
;   How often we should run the checks and submit the results.
interval=5
;
;# ENCRYPTION METHOD
;   This option determines the method by which the send_nsca client will encrypt the packets it sends 
;   to the nsca daemon. The encryption method you choose will be a balance between security and 
;   performance, as strong encryption methods consume more processor resources.
;   You should evaluate your security needs when choosing an encryption method.
;
; Note: The encryption method you specify here must match the decryption method the nsca daemon uses 
;       (as specified in the nsca.cfg file)!!
; Values:
;	0 = None	(Do NOT use this option)
;	1 = Simple XOR  (No security, just obfuscation, but very fast)
;   2 = DES
;   3 = 3DES (Triple DES)
;	4 = CAST-128
;	6 = xTEA
;	8 = BLOWFISH
;	9 = TWOFISH
;	11 = RC2
;	14 = RIJNDAEL-128 (AES)
;	20 = SERPENT
;encryption_method=14
;
;# ENCRYPTION PASSWORD
;  This is the password/passphrase that should be used to encrypt the sent packets. 
;password=
;
;# BIND TO ADDRESS
;  Allows you to bind server to a specific local address. This has to be a dotted ip adress not a hostname.
;  Leaving this blank will bind to "one" local interface.
; -- not supported as of now -- 
;bind_to_address=
;
;# LOCAL HOST NAME
;  The name of this host (if empty "computername" will be used.
;hostname=
;
# NAGIOS SERVER ADDRESS
;  The address to the nagios server to submit results to.
nsca_host=198.162.1.1

# NAGIOS SERVER PORT
;  The port to the nagios server to submit results to.
nsca_port=5667


;# CHECK COMMAND LIST
;  The checks to run everytime we submit results back to nagios
;  Any command(alias/key) starting with a host_ is sent as HOST_COMMAND others are sent as SERVICE_COMMANDS
;  where the alias/key is used as service name.

una vez realizados estos cambios guardamos y cerramos el archivo, y para terminar solamente debemos iniciar el servicio NSClient++ desde el administrador de servicios de windows