The Multi-Network option can be used to define if the individual networks (On a single Pro Cloud-Link) are allowed to communicate with each other. The Cloud-Link would need to have more than 1 network defined for this to work. You will be able to manage settings for each individual network in MDS Manager for that Cloud-Link.
For example, you can configure the Pro Cloud-Link to have 4 networks (The 8 LAN ports automatically become segmented into pairs of 2s). Then, you can turn on Multi-Network routing for each of the segments if you wanted them to be able to communicate to other segments on this same Pro.
Network 1 (Ports 1 and 2) - Clients (multi-network routing ON)
Network 2 (Ports 3 and 4) - Server (multi-network routing ON)
Network 3 (Ports 5 and 6) - WiFi Access Point traffic (multi-network routing ON)
Network 4 (Ports 7 and 8) - Accounting traffic (multi-network routing OFF)
In this implementation, all networks would be able to communicate with each other except for the Accounting ports.
If you use VLANs, Keep in mind that the Cloud-Link currently does not support VLAN tagged traffic. To leverage VLANs with a Cloud-Link, traffic is required to be delivered in an untagged form to the corresponding ports on the Cloud-Link. One cable per network/segment to the corresponding ports on the Cloud-Link Pro.
Note: This Multi-Network feature should not be confused with Multi-Site orders. They are separate features and configured in different locations.