BrikerMan

It works like a charm, Thanks @Michael Meiszl.

I turn off the "flow control" using using this tutorial. And the 10G network is working after 3 reboot and 1 power off. It seems the issue resolved. Thanks a lot for your help. I will give it two more days for testing before tag this issue as resolved.

Thanks for your advise. I am directly connected 2 10G card. Ubuntu Server <------- cable -------> Unraid NAS, without additional switch. I am suspected on the hardware too. But I never have this issue before I switch to the Unraid system. And it is 100% reproducible issue. So I am get confused on why.

I have installed the 10 GbE network, which setup a direct link with my Ubuntu server. It works perfectly and can transfer up to 1GB/s. But here is a wired issue. On every Unraid system reboot, I need to unplug the SFP+ adapter and replug it. Otherwise It won't connect to my Ubuntu server. Just unplug the cable and replug isn't work. And this setup worked perfectly with the previous with Synology DSM 6.2.1 system. Current Unraid System version: 6.9.2 Here is my Interface Config 10G Interface Config: Enable bonding: No Enable bridging: Yes Bridging members of br1: eth1 Network protocol: IPv4 only IPv4 address assignment: Static IPv4 address: 192.168.10.5/24 IPv4 default gateway: Desired MTU: 1500 Enable VLANs: Here is pci info 03:00.0 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01) 03:00.1 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01)