Nagios Support Forum

I've successfully used Distributed monitoring between a Nagios (client) machine and an Icinga (server) machine. NSCA encryption is XOR.

When I try to do the same with NagiosXI as the server and Nagios as the client I get the following in /var/log/messages

Jun 27 13:08:49 SRV-NagiosXI xinetd[15177]: START: nsca pid=2744 from=::ffff:<nagios client ip>
Jun 27 13:08:49 SRV-NagiosXI nsca[2744]: Handling the connection...
Jun 27 13:08:50 SRV-NagiosXI nsca[2744]: Dropping packet with invalid CRC32 - possibly due to client using wrong password or crypto algorithm?
Jun 27 13:08:50 SRV-NagiosXI xinetd[15177]: EXIT: nsca status=0 pid=2744 duration=1(sec)

I have NagiosXI set to decrypt using XOR and the passwords are the same. Any suggestions?

Server - NagiosXI 2011R3.1, Nagios Core 3.4.1, NagiosQL 3.0.3
Client - Nagios Core 3.3.1

Are you sure you are using the same password and decryption method on the client?

Checked them on both sides many times, and they match.

Try restarting the daemon:
Hope this helps.

I've tried that with no luck either.

Is it possible that the XOR encryption in Nagios is different than the decryption of XOR in NagiosXI? I know it all comes from NSCA and libmcrypt, but could there be a subtle difference?

There shouldn't be, but you could be using different versions of NSCA

To check on the sending machine run On the receiving machine run Lets look at the versions of both and compare

On the NagiosXI server:

NSCA - Nagios Service Check Acceptor
Copyright (c) 2000-2007 Ethan Galstad (www.nagios.org)
Version: 2.7.2
Last Modified: 07-03-2007
License: GPL v2

On the Nagios client:

NSCA Client 3.0-dev
Copyright (c) 2010-2012 Icinga Development Team and Community Contributors (http://www.icinga.org)
Copyright (c) 2000-2007 Ethan Galstad (www.nagios.org)
Last Modified: 10-05-2011
License: GPL v2

Here's my theory now...I downloaded the NSCA package from Icinga, and compiled it using the icinga user and icinga group. I believe I have to redo all of this using an NSCA package from Nagios instead.

Success! I had to use the Nagios NSCA, NOT the Icinga NSCA.

Thanks for everyone's help!

Glad you got it working..

Using Icinga's NSCA apparently can have undesirable results...