Some common causes for this problem are:
- Legacy devices The devices are running legacy (pre-4.0) firmware. These devices will not be auto-discovered, they must be manually enrolled via IP address. Note that legacy devices cannot route audio between subnets.
- Multi-subnet system The devices are in a different subnet to the DDM server, but you do not have DNS running on the network, or your DNS service is not correctly configured
- The devices are on the same subnet as the DDM server, but you do not have the Dante Discovery Service enabled (or DNS running)
- Multicast traffic is being blocked or filtered Dante discovery relies on multicast (mDNS / SAP). If switches have IGMP snooping misconfigured, or multicast filtering enabled without a querier, devices may not be visible.
- Incorrect VLAN configuration Devices and the DDM server may be in different VLANs without proper routing or multicast forwarding configured between them.
- Firewall rules blocking required ports Local firewalls (on the DDM server or network) may block Dante discovery or DDM communication ports (e.g., mDNS 5353, DDM control ports). See Dante Ports and IP's
- Device is already enrolled in another DDM domain A device can only belong to one DDM domain at a time. If previously enrolled elsewhere, it won’t appear for discovery.
- Clocking or PTP domain issues While not always preventing discovery, severe PTP or clocking conflicts can cause devices to behave unpredictably or not register properly.
- Duplicate IP addresses or IP conflicts If two devices share the same IP, discovery can fail or show inconsistent results.
- Incorrect subnet mask or gateway configuration Even if IPs look similar, mismatched subnet masks can prevent proper communication with the DDM server.
- Dante interfaces disabled or misconfigured Some devices allow Dante to be disabled or set to redundant mode incorrectly, preventing visibility.
- Incorrect interface selected Ensure that within the DDM itself under Network and Security, the correct network interface is selected
- Network QoS or bandwidth issues Excessive congestion or incorrect QoS settings can disrupt discovery traffic.
- mDNS disabled on endpoints or network Some enterprise networks explicitly disable mDNS, which will stop auto-discovery unless DNS Discovery Service is used.
- Device boot state or fault condition Devices stuck in bootloader mode, firmware update mode, or with hardware faults may not advertise themselves.
If after correcting all problems related to the above conditions your devices are still not showing up in DDM, try enrolling them using their IP addresses. If this fails, contact your IT administrator.