Per the README that comes with NSCA is a complete description of how to setup the central server. I did nothing more, nothing less, than what is in that file.
The binaries will be located in the src/ directory after you
run 'make all' and will have to be installed manually.
In other words, take the nsca file and put it someplace like /usr/local/nagios/bin/
Add a line to your /etc/services file as follows (modify the port
number as you see fit)
nsca 5667/tcp # NSCA
***** XINETD *****
If your system uses xinetd instead of inetd, you'll probably
want to create a file called 'nsca' in your /etc/xinetd.d
directory that contains the following entries (a sample config
file called nsca.xinetd should be created in the root folder of
the distribution after you run the configure script):
# default: on
# description: NSCA
flags = REUSE
socket_type = stream
wait = no
user = <user>
group = <group>
server = <nscabin>
server_args = -c <nscacfg> --inetd
log_on_failure += USERID
disable = no
only_from = <ipaddress1> <ipaddress2> ...
Add entries to your /etc/hosts.allow and /etc/hosts.deny
file to enable TCP wrapper protection for the nsca service.
This is optional, although highly recommended.
So, now that you have nsca defined in xinetd it will be started when you restart xinetd. It will then be listening on some port. When data is sent to nsca, it then passes the info to nagios. The format of that data is [tab][tab][tab][newline]
If the data format matches something on the central server, then the host/service information is displayed. But of course, if you have no host/service descritiption that matches, then there is no way it's going to display anything. Check your nagios.log file for errors.