Some more or less fundamental problems of Zabbix:
- Transfers between server and agent are un-authenticated and un-encrypted. zabbix_sender connects to the right TCP Port and that's it.
- values are being transferred one by one. If I do a “df” and get 10 values for 10 mounted filesystems, then the zabbix server will make 10 TCP connections to get those values and will call 10 times df