Nagios Support Forum

Posted: **Thu Sep 20, 2012 7:57 am**

Hi

I have been running Nagios XI and NSClient++ on about 9 remote MS Windows servers for a year now with great success. However, yesterday my Nagios server blew up, and I could not successfully boot the hard drive in another server, so I had to reinstall from scratch. I ended up with CentOS 5.8 running Nagios XI 2011R3.3

The nsca version is 2.9.1 and the NSClient++ on the remote windows servers remains unchanged, although I did update one to NSCP 0.4.0.183-Win32 to see if that made any difference.

The error I am getting in /var/log/messages is :-
Handling the connection...
Dropping packet with invalid CRC32 - possibly due to client using wrong password or crypto algorithm.
EXIT nsca status=0 pid=12264 duration=0(secs)

I know the password and is the same across the servers and Nagios, and the encryption method is DES (2) on all.

I am really stuck now, so any help would be appreciated.

Regards Stewart

Posted: **Thu Sep 20, 2012 11:36 am**

We have found on some systems NSClient just isn't playing nicely with NSCA 2.9.1

You can downgrade NSCA to 2.7.2 by running the following

Code: Select all

wget http://assets.nagios.com/downloads/nagiosxi/agents/nsca-downgrade.tar.gz
tar xvf nsca-downgrade.tar.gz
cd nsca
./upgrade

Posted: **Fri Sep 21, 2012 2:56 am**

Amazing,
After three days of tearing my hair out your solutions solved the issues. All my external servers are registering perfectly. Thank you so much!!

Nagios Support Forum

Dropping packet with invalid CRC32...

Dropping packet with invalid CRC32...

Re: Dropping packet with invalid CRC32...

Re: Dropping packet with invalid CRC32...