usage:
check_find_new_hosts [-v+] [-x] [-s] /dir ip netmask contact
where:
dir is the directory containing the .cfg files (and .skip files if you want to skip certain hosts)
ip is an ip in the range you want to scan
netmask is an integer standing for the netmask eg:24 = 255.255.255.0
contact is the contact group you want new hosts found to answer to.
example:
./check_find_new_hosts -v /etc/nagios/network 192.168.10.129 25 domain-admins
when troubleshooting how this is working use -vv or -vvv from a command line
for more information consult the very very verbose help (may want to | less on a small screen):
./check_find_new_hosts -vvvh
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check_find_new_hosts requires the following (that I know of):
1) fping is installed at /usr/sbin/fping
2) traceroute is installed at /usr/sbin/traceroute
3) Nagios must parse a directory of cfg files, rather than implicitly listing the files eg:
cfg_dir=/etc/nagios/hosts_hostgroups_and_services
rather than:
#cfg_file=/etc/nagios/contactgroups.cfg
#cfg_file=/etc/nagios/contacts.cfg
#cfg_file=/etc/nagios/dependencies.cfg
#cfg_file=/etc/nagios/escalations.cfg
#cfg_file=/etc/nagios/hostgroups.cfg
...
4) the service generic_service must be defined (the following is what I use):
define service{
name generic-service ; The 'name' of this service template, referenced in other service definitions
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
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
register 0 ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
}
5) the 24x7 time period should be defined
define timeperiod{
timeperiod_name 24x7
alias 24 Hours A Day, 7 Days A Week
sunday 00:00-24:00
monday 00:00-24:00
tuesday 00:00-24:00
wednesday 00:00-24:00
thursday 00:00-24:00
friday 00:00-24:00
saturday 00:00-24:00
}
6) a contact group is defined
7) the network that is being looked at can be pinged
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This check would be installed as multiple commands(one for every subnet) and can then be added as a check to whatever host makes the most sense to have it on(I have it as a check on the Nagios host machine)
For example, if you wanted to check the network 192.168.0.x (let's say your servers) and all you host and service definitions (at least all of them for this subnet) are in the directory /etc/nagios/network and the contact group you are using is "admins" you would need the following:
define command{
command_name check_find_new_hosts_servers
command_line /usr/lib/nagios/plugins/contrib/check_find_new_hosts -v /etc/nagios/network 192.168.0.0 24 admins
}
if you also wanted to check 192.168.10.[129-255] (how about these are your domain controllers) with the contact group "domain-admins":
define command{
command_name check_find_new_hosts_domain
command_line /usr/lib/nagios/plugins/contrib/check_find_new_hosts -v /etc/nagios/network 192.168.10.129 25 domain-admins
}
You would also need services defined to check these:
define service{
use generic-service
host_name main-server-router
service_description FIND_NEW_HOSTS
is_volatile 0
check_period 24x7
max_check_attempts 3
normal_check_interval 5
retry_check_interval 1
contact_groups admins
notification_interval 120
notification_period 24x7
notification_options c,r
check_command check_find_new_hosts_servers
}
define service{
use generic-service
host_name main-domain-controller
service_description FIND_NEW_HOSTS
is_volatile 0
check_period 24x7
max_check_attempts 3
normal_check_interval 5
retry_check_interval 1
contact_groups domain-admins
notification_interval 120
notification_period 24x7
notification_options c,r
check_command check_find_new_hosts_domain
}
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once run it may generate the following files (so either run it and generate these files or steer away from them):
x.y.cfg where x.y is from the ip address of the host found: 192.168.15.32 would be put in 15.32.cfg
name.cfg where name is from the fdqn: freddy.mybuddy.com would be put in freddy.cfg
nagios_hostgroup_unknown.cfg (expects this file either to not exist or to contain 1 hostgroup):
define hostgroup {
hostgroup_name undefined
alias Non-Configured
members freddy,betsy,bob,...
}
use "--nowrite --stdout" ( -xs ) as a command line option to write these to stdout instead of to files if you just want to test it or
use -vvx to show what it is doing but don't write any files and don't show the files on stdout