Nagios Support Forum

Posted: **Sun Sep 02, 2018 4:34 pm**

Hello, first time here on the forum. Been using nagios for 2-3 years.
While trying to help the community, by doing tutorial video about making a complete system from nagios core. Graph+ notification...
I'm having a problem that seem easy but I cannot go through.

Install the lastest nagios and pluging in a new VM ubuntu 18.04 and NSClient++ on another Windows 10.

I'm able to check the server itself by doing the following command.

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./check_nrpe -H 127.0.0.1
NRPE v3.2.1

When I try to do the same thing on the Windows host with NSClient it's giming me this error.

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./check_nrpe -H 192.168.7.177
CHECK_NRPE: (ssl_err != 5) Error - Could not complete SSL handshake with 192.168.7.177: 1

I've tried a working configuration and it still doing the same error. I even try to downgrade the NSClient Version to 4.xxxx . So I don't think it's a NSClient issue. Someone has an idea?

Here the basic config of NSClient.

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[/settings/default]
allowed hosts = 192.168.7.157
[/settings/NRPE/server]
ssl options = 
verify mode = none
insecure = true
[/modules]
NRPEServer = 1

192.168.7.157 = Nagios test server.
192.168.7.177 = Windows 10 + NSClient.

Posted: **Tue Sep 04, 2018 11:44 am**

Here's a post from @lmiltchev in the customer support section:
https://support.nagios.com/forum/viewto ... 09#p258830

lmiltchev wrote: Try the following:

1. Commend out these two lines in nsclient.ini file:
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; ssl options = no-sslv2,no-sslv3
; verify mode = peer-cert
2. Add the following line under the [/settings/NRPE/server] section:
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allowed ciphers = ALL:!MD5:@STRENGTH
3. Save, exit, and restart the nsclient++ service.

Did this help?

Give those a try and let us know if they don't work.

Posted: **Tue Sep 04, 2018 12:15 pm**

Thanks @mcapra for the help.

The ssl setting for NRPE is missing so under this section

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[/settings/NRPE/server]

Add this

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use ssl = 1

Save the file and restart NSClient++ which will make sure SSL is enabled in the agent.
Also, make sure port 5666 is enabled through the firewall.

If it still doesn't work, post the errors from the nsclient.log file on the Windows system to the post so we can view them.

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