This program is designed to accept passive service check results from
clients that use the send_nsca utility and pass them along to the
Nagios process by using the external command
interface. The program can either be run as a standalone daemon or as
a service under inetd. If you have libmcrypt installed on your systems,
you can choose from multiple crypto algorithms (DES, 3DES, CAST, xTEA,
Twofish, LOKI97, RJINDAEL, SERPENT, GOST, SAFER/SAFER+, etc.) for
encrypting the traffic between the client and the server.
Encryption is important in this addon, as it prevents unauthorized users
from sending bogus check results to Nagios. Read the included SECURITY
document for more information.