Nagios Support Forum

SimonMaton wrote:Hi Folks, I am running Nagios on a RPi4. I am trying to monitor the status of a Siemens PLC (Programmable Logic Controller), I get a status that the device is down with the following error:

check_ping: Invalid hostname/address - [192.168.102.200]

When I run the check_ping command from a terminal I get this:

pi@PTGM2:/usr/local/nagios/etc/objects $ /usr/local/nagios/libexec/check_pop -H 192.168.102.200
connect to address 192.168.102.200 and port 110: Connection refused

But if I run a normal ping, It is successful.

pi@PTGM2:/usr/local/nagios/etc/objects $ ping 192.168.102.200
PING 192.168.102.200 (192.168.102.200) 56(84) bytes of data.
64 bytes from 192.168.102.200: icmp_seq=1 ttl=30 time=0.422 ms
64 bytes from 192.168.102.200: icmp_seq=2 ttl=30 time=0.366 ms
64 bytes from 192.168.102.200: icmp_seq=3 ttl=30 time=0.346 ms
^C
--- 192.168.102.200 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 43ms
rtt min/avg/max/mdev = 0.346/0.378/0.422/0.032 ms
pi@PTGM2:/usr/local/nagios/etc/objects $

I'm new to Nagios, so any help appreciated. My initial thought is that the check_ping command is asking too many questions of the PLC that it can't answer! Is this feasible and if so, how do I dumb it down to a very basic ping command etc. please?

Regards Simon