Access nagios doesn’t show anything/offline/cant be reache, but nagios server ping is reachable and nagios service is running :
httpd service is not running
check the status : systemctl status httpd
start the service : systemctl start httpd
check log : /var/log/httpd/error_log
Successfully access nagios core but it shows not running :
Nagios service is not running
check the status : systemctl status nagios
start the service : systemctl start nagios
start the service for old version : /etc/rc.d/init.d/nagios start
Error : Check_NRPE: (ssl_err != 5) Error – Could not complete SSL Handshake with 192.168.1.1:1
this error due to issue of SSL Handshake, can be fixed by solving SSL Handshake or disable the SSL.
fix the SSL :
generate key and save it 🙁 C:\Program Files\NSClient++\security\nrpe_dh_2048.pem)
command nagios server : openssl dhparam -C 2048 2> /dev/null/sed -n ‘/BEGIN/,/END/p’
add nagios.ini file :
; # DH KEY
dh = ${certificate-path}/nrpe_dh_2048.pem
disable SSL :
add -n on command (/usr/local/nagios/libexec/check_nrpe -H 192.168.1.1 -n)
add on nsclient.ini :
[/settings/NRPE/server]
use ssl = 0 (ignore ssl, nagios server should be not use ssl (add “-n” on command check)
Error : CHECK_NRPE: Invalid packet version received from server.
error due to different version of NRPE
how to fix it : add -2 on nagios check command to force to use nrpe version 2 (/usr/local/nagios/libexec/check_nrpe -2 -H 192.168.1.1)
Service checked time out
could be due to remote node need time to check more than timeout value.
increase timeout nrpe / external script (timeout = xx)
dont forget to increase the next check time if the timeout value more than next check time valua.
Error : DISK CRITICAL – /sys/kernel/debug/tracing is not accessible: Permission denied
/usr/lib/nagios/plugins$ sudo chmod u+s check_disk
-rwsr-xr-x 1 root root
Error : CHECK_NRPE: Receive header underflow – only 0 bytes received (4 expected).
due to the command check nagios without SSL, but on client/remote node side still active the SSL.
Solution :
nsclient.ini file add -> use ssl=false
Error : Exception processing request: Request contained arguments (not currently allowed, check the allow arguments option).
nsclient.ini add -> allow arguments = true
allow nasty characters = true
