In order for the auto-discovery feature to work, your network must have Multicast communication enabled. 

The Server application initiates a continuous sequence of requests to try and get all the devices sharing the same network setup to respond back to it with detailed information on what methods to use in order to add them to the VMS. 

Added devices will appear in the resource tree under the server it was associated with.

How to enable/disable Auto-discovery:

Auto-discovery is enabled by default. To disable or re-enable this feature, do the following:

1. In the Desktop client from the Main Menu (≡) select System Administration.
2. In the General tab, find the System Settings section.
3. Check the box for “Enable cameras and servers auto-discovery and automated camera status check”.

In addition to continuously discovering new cameras and servers, the Server application also sends discovery requests to get status updates from existing cameras. These two factors can cause problems in environments with several systems in the same network, resulting in all systems discovering all cameras on the network and creating a lot of unwanted network traffic. As a result, auto-discovery is usually disabled in such cases.

In order to free up network resources, the number of transactions between servers and devices are minimized. As a result, both manually added and auto-discovered devices will be shown as offline, unless anything below is true:

• Auto-discovery is enabled
• The camera stream is currently being viewed or recorded
• the camera stream was viewed or recorded prior to disabling auto-discovery
• Failover is enabled on any server 

Please, refer to the table below: