check_NRPE gave "Received 0 bytes from daemon"

[caterpillartce]

Hello,

I am trying to use check_NRPE to monitor physical memory usage on a windows server. This might be the first time check_nrpe is used. Is there anything I need to do to "enable" it as when I "Run the Check Command" when defining the service in CCM, it gives an error "Received 0 bytes from daemon". The nsclient log file has

"2017-07-21 11:57:50: error:c:\source\nscp\include\socket/connection.hpp:243: Failed to establish secure connection: unknown protocol: 252"

This is in NSCLIENT.INI:

[/settings/NRPE/server]

; Undocumented key
ssl options = no-sslv2,no-sslv3

; Undocumented key
; verify mode = peer-cert

; Undocumented key
insecure = true

Thanks!

[ssax]

Please attach your entire nsclient.ini so that we can review it, here is generally what needs to be set:

Code: Select all

[/modules]
; NRPEServer - A server that listens for incoming NRPE connection and processes incoming requests.
NRPEServer = 1


; TODO
[/settings/NRPE/server]

; ALLOW INSECURE CHIPHERS and ENCRYPTION - Only enable this if you are using legacy check_nrpe client.
insecure = 1

; COMMAND ALLOW NASTY META CHARS - This option determines whether or not the we will allow clients to specify nasty (as in |`&><'"\[]{}) characters in arguments.
allow nasty characters = 1

; EXTENDED RESPONSE - Send more then 1 return packet to allow response to go beyond payload size (requires modified client if legacy is true this defaults to false).
extended response = 0

; PORT NUMBER - Port to use for NRPE.
port = 5666

; COMMAND ARGUMENT PROCESSING - This option determines whether or not the we will allow clients to specify arguments to commands that are executed.
allow arguments = 1

; ENABLE SSL ENCRYPTION - This option controls if SSL should be enabled.
use ssl = 1

Also, what version of NSClient++ are you using? You can find it listed next to the name in the add/remove programs or programs and features section of the control panel.


Thank you

[caterpillartce]

hi, I added port and allow argument based on above. Restarted NSClient service. But it did not help. I will PM you our nsclient.ini. Its version is 0.4.4.19.

Thanks

[tacolover101]

i feel like these contradict each other -

Code: Select all

; Undocumented key
ssl options = no-sslv2,no-sslv3

; Undocumented key
; verify mode = peer-cert

; Undocumented key
insecure = true

try commenting out ssl options if you're fine with insecure mode.

also post your nsclient.log as if it's SSL related, this will usually have more information.

[lmiltchev]

Are you calling an external script via check_nrpe?

In the majority of the cases, you would also need to set the following:

Code: Select all

CheckExternalScripts = 1

in the [/modules] section, and:

Code: Select all

allow nasty characters = 1
allow arguments = 1

in [/settings/external scripts] section.

[ssax]

Please post the entire check command you are running from the XI server, you can get it from the Run Check Command button when editing the service.

Thank you

[caterpillartce]

I did all the above, but it is still failing with the same error. Attached please find the nsclient.ini and log file. I removed the allowed hosts for security in the ini file. The error about check_time in the log seems to have been there for ever and not related to check_NRPE.

Thanks!

[caterpillartce]

And this is the check command: (I just wanted to monitor physical memory usage)

$USER1$/check_nrpe -H $HOSTADDRESS$ -n -c CheckMem -a type=physical MaxWarn=$ARG1$ MaxCrit=$ARG2$ ShowAll=long

[lmiltchev]

Can you post the entire nsclient.ini file? You can redact it / remove sensitive info.

Run the following commands from the Nagios XI server and show the output:

Code: Select all

/usr/local/nagios/libexec/check_nrpe -H <client ip>
/usr/local/nagios/libexec/check_nrpe -H <client ip> -c alias_mem
/usr/local/nagios/libexec/check_nrpe -H <client ip> -c CheckMem -a type=physical MaxWarn=$ARG1$ MaxCrit=$ARG2$ ShowAll=long

[caterpillartce]

The attached nsclient.ini is the entire file. The only thing I removed was the IP addresses of the allowed hosts.
I ran the commands on the Linux Nagios server and they all seemed to have worked fine. Attached is the screenshot.
Thanks!