If you want to prevent LAN Clients from identifying your Zyxel devices in the same broadcast domain with our Zyxel One Network (ZON) Software, then you have to block the destination multicast MAC address:
01:A0:C5:11:11:11
ZDP is used by ZON our Zyxel One Network Utility.
You can find some information and the download here:
Zyxel One Network Utility (ZON)
What is a broadcast domain?
A network without VLAN's or router will be a broadcast domain.
1) Configure Classifier [ACL] Rule
Navigate to:
SECURITY > ACL > Classifier > Classifier Setup
This setting can be set on a switch via ACL (Classifier) and it's policy rule.
2) Verify your Result
Navigate to:
SECURITY > ACL > Classifier > Classifier Status