Nagios Support Forum

nmpa command from nagios sercer itself:
-bash-4.1# nmap -sU -p 5666 168.162.97.143

Starting Nmap 6.47 ( http://nmap.org ) at 2017-03-20 10:53 EDT
mass_dns: warning: Unable to determine any DNS servers. Reverse DNS is disabled. Try using --system-dns or specify valid servers with --dns-servers
Nmap scan report for 168.162.97.143
Host is up (0.00023s latency).
PORT STATE SERVICE
5666/udp open|filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 0.26 seconds
-bash-4.1# hostname
ssbpops01.ssb.sungard.com
-bash-4.1#

Can you run this too since JMX is going to utilize this port directly? Then, as requested, post the JMX configuration settings that are running on the client side.

Thanks @rkennedy!