CHECK_NRPE: (ssl_err != 5) Error

[kabamaru]

Hello all

I'm trying to check that SSH is running on a remote host using nrpe.

[root@astor plugins]# ./check_nrpe -H hostname -c check_ssh -p 22
But I get this error:
CHECK_NRPE: (ssl_err != 5) Error - Could not complete SSL handshake with <IP_address:1>

The remote host is running centOS7. Does anyone know what it means and how it can go away?

Thank you

[kg2857]

Try running check_nrpe -h and look at the SSL options.

[kabamaru]

Hi

Thanks for your suggestion. I've tried all the -S options but the same message was returned.
I then tried the -n flag (don't use SSL) and I got this message:

CHECK_NRPE: Invalid packet version received from server.

This is NRPE on the client

[root@alinda libexec]# systemctl status nrpe
● nrpe.service - Nagios Remote Plugin Executor
Loaded: loaded (/usr/lib/systemd/system/nrpe.service; enabled; vendor preset: disabled)
Active: active (running) since Fri 2023-11-24 12:51:05 GMT; 3 days ago
Docs: http://www.nagios.org/documentation
Main PID: 31044 (nrpe)
Tasks: 1
Memory: 684.0K
CGroup: /system.slice/nrpe.service
└─31044 /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -f

Nov 24 12:51:05 alinda systemd[1]: Started Nagios Remote Plugin Executor.
Nov 24 12:51:05 alinda nrpe[31044]: Starting up daemon
Nov 24 12:51:05 alinda nrpe[31044]: Server listening on 0.0.0.0 port 5666.
Nov 24 12:51:05 alinda nrpe[31044]: Server listening on :: port 5666.
Nov 24 12:51:05 alinda nrpe[31044]: Warning: Daemon is configured to accept command arguments from clients!
Nov 24 12:51:05 alinda nrpe[31044]: Listening for connections on port 5666
Nov 24 12:51:05 alinda nrpe[31044]: Allowing connections from: 127.0.0.1,128.40.177.194
Nov 27 12:04:07 alinda nrpe[9722]: Error: (!log_opts) Could not complete SSL handshake with 128.40.177.194: 1
Nov 27 12:04:07 alinda nrpe[9724]: Error: (!log_opts) Could not complete SSL handshake with 128.40.177.194: 1

Also, NRPE on the client was installed from source using this super How-To
https://support.nagios.com/kb/article/n ... e-515.html

[gwesterman]

Hi @kabamaru,

If you haven't already, I would check out this article on the common reasons and corresponding solutions for this issue.

Let us know if this helps!

Thank you!

[kabamaru]

Hi gwesterman

It is working now. I had nrpe installed using yum. I re-installed it using ./configure --enable-ssl.

Many thanks for pointing me to the right direction.