NRPE - Return Code Of 126 Is Out Of Bounds - Plugin May Not Be Executable

Problem Description

This KB article addresses the following NRPE error:

Return Code Of 126 Is Out Of Bounds - Plugin May Not Be Executable

Assumed Knowledge

The following KB article contains an explanation of how NRPE works and may need to be referenced to completely understand the problem and solution that is provided here:

NRPE - Agent and Plugin Explained

Troubleshooting The Error

Many times when a plugin is downloaded from the Nagios Exchange and copied to the remote host, it will not have executable permissions.  You can verify this by getting a long-listing of the libexec plugin directory. For this example will will be using the command check_foo.sh.  On the remote host execute the following command:

ls -l /usr/local/nagios/libexec

You should see a listing similar to:

-rwxr-xr-x. 1 root   root     4173 Nov 21 01:39 check_bl
-rw-r--r--. 1 root   root     2289 Nov 21 01:39 check_foo.sh

The far left column of the listing are the permissions for each file. If you noticed, check_foo.sh is missing an "x" in a few places.  These are executable permissions and can easily be added to the file using the following command:

chmod +x /usr/local/nagios/libexec/check_foo.sh

Remember that check_foo.sh is just an example, you will change /usr/local/nagios/libexec/check_foo.sh to the actual name and path to your plugin that is missing executable permissions. 

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

http://support.nagios.com/forum/