Why the SFP+ DAC 1 meter can’t work with NIC card X520 on Netgear M4300, the other end is QNAP device?

Solution:Check 10Gtek production and shipment record, to confirm the SFP+ DAC cable encoding is 100% compatible with Netgear M4300. Ask the customer to test with other qualified DAC cable in the same environment or test 10Gtek SFP+ DAC in other environment that confirmed available. It turns out that IP address conflicts have caused this problem. After changing the IP, the connection and transmission are normal.