Monitoring remote Server service via Zabbix Agent through a VPN

[IteaAgain]

Hello,

i have a problem that i have thought is easy to solve via the "Zabbix Agent" (NOT via Simple Checks) function net.tcp.service, unfortunatly it is not working :-(

Environemnt
In my LAN i have a dedicated Gateway-Server which creates a VPN to a remote Server to access a SAP service there.
I wanted to have a Zabbix Item that checks those SAP service via a net.tcp.service(tcp,<SAP Server IP>)

The VPN / SAP Server service is ONLY accessible on the Gateway-Server itself (localhost) but not from the LAN. Therefore i cannot use a "Simple Check" from my Zabbix Server.

if i do a "telnet <SAP Server IP> 3200" from localhost/Gateway Server i got a connection to the SAP Server. But if i configure a Zabbix Agent Item "net.tcp.service(tcp,<SAP Server IP>,3200)" it does not work. It is always "0".

Of course the Gateway Server with the VPN to the SAP Server has Zabbix Agent installed and it is working fine.
Of course i have created the item in question for this Gateway Server Host in Zabbix.

Any idea why it is not working?

Is it true that the Zabbix Agent of the Gateway Server should process that "net.tcp.service(tcp,<SAP Server IP>,3200)" when selecting "Zabbix Agent" instead of "Simple Check"? or did i misunderstood this?

Any help is really needet. I found one workaround which i haven't tested yet because i thought it should be not needet. See the workaround: https://ma.ttias.be/zabbix-monitor-a...-zabbix-agent/

[IteaAgain]

OK, thank you for your help.

I use the external script now. Thoise net.tcp.service or net-tcp.port stuff seems to work ONLY from Server/Proxy, but not from Agent. Maybe i#m unable to read the manual or this stuff just don't work.