Nagios Support Forum

Hi

I have just noticed this on one of our Nagios Servers
CHECK_NRPE: Receive header underflow - only 0 bytes received (4 expected).

This message shows against
/var/log/disk usage
CPU
Memory Usage

But the Monitor for Squid proxy Server shows as OK

The Squid Monitor is just standard Check_NRPE as the check command
and in $ARG1$ it just says check_squid

The others that show with the above error use defined parameters
for example
check_cpu
-a '-w 85 -c 95'

We were getting a message before I wonder if that has anything to do with this, since we upgraded to CentOS7 and nagios 5.7.1 we were getting the following message
CHECK_NRPE: Invalid packet version received from server

So the the >_commands I added the -2 to the check_nrpe command and that resolved the errors

Thansk

I removed the -2 from the check_nrpe and I got back the message
CHECK_NRPE: Invalid packet version received from server

But only seems to be the windows servers so I wonder if this could be related to the version of the windows agent we are running
at present we are running 0.4.3.73
Is there a later version of the agent that I could test with

Thanks

Hi,

So in the latest version of NRPE the default packet type has been upgraded to version 4. and the check_nrpe plugin on the Nagios XI server was upgraded to the latest version in 5.7.x. However, you can add the -2 flag to using the legacy packet type. Does adding this option resolve the issue for you?

Regards,
Benjamin

Reference:
https://github.com/NagiosEnterprises/nr ... ANGELOG.md

Hi Benjamin
Adding the -2 to the check_nrpe allows the Windows Monitors to report correct and not show this message
CHECK_NRPE: Invalid packet version received from server

Is there a newer version of the Agent I wonder if we are seeing this as we are running an older version of the agent on our Windows 2016 Servers


But on some of the Linux Servers

Not sure if its OS related but the system I am looking at is CentOS7
I am seeing the following message

CHECK_NRPE: Receive header underflow - only 0 bytes received (4 expected).

Thanks

Hi,

For the Windows/NSClient questions, I would recommend sticking with that version of NSCLient, For the NSClient wizard in Nagios XI, we provide links to install version v0.4.4.

The error you're getting on the Linus server is usually related to settings for passing arguments from Nagios XI to NRPE.

Make sure you have the following option set in the nrpe.cfg file (restart the nrpe service if making any changes). If that's not the issue, did you enable command arguments when compiling NRPE?

Benjamin

Reference:
https://support.nagios.com/kb/article/n ... e-515.html

Hi Benjamin

Thanks for the info you can mark this as closed

Thanks

mccrakem wrote:Hi Benjamin

Thanks for the info you can mark this as closed

Thanks

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