M1 Mac or OWC - cannot handle 2 10GbE Adapter?

[GoetzPhil]

3 years ago I bought the OWC Thunderbolt Hub and till now it works great.
I have my old NAS connected via Thunderbolt to 10GBit Adapter and it works perfect.

Now I bought a 2nd NAS with 10GbE port. So I also bought a 2nd Adapter to connect my new NAS via Thunderbold to 10GbE.
But its not working as I expected.
After testing all components I see that if I use only 1 Adapter it works - but whichever Adapter I connect second - that connection isnt working.

So my question is, does either the 2020 iMac M1 not support two 10GbE Adapter together, or is it maybe the old OWC dock that can only handle 1 10GbE Adapter but not 2.

Anyone experienced similar?

 

[Bigwaff]

So my question is, does either the 2020 iMac M1 not support two 10GbE Adapter together, or is it maybe the old OWC dock that can only handle 1 10GbE Adapter but not 2.

Have you tried connecting one adapter directly to the iMac and one adapter to the hub?

 

[GoetzPhil]

Yes, same result even when I switch them over on the ports.

 

[joevt]

3 years ago I bought the OWC Thunderbolt Hub and till now it works great.
I have my old NAS connected via Thunderbolt to 10GBit Adapter and it works perfect.

Which OWC hub/dock?
Which NAS?
Which 10 GbE Adapter? Is it a USB or Thunderbolt adapter?
Which Thunderbolt port is the adapter connected to?

Now I bought a 2nd NAS with 10GbE port. So I also bought a 2nd Adapter to connect my new NAS via Thunderbold to 10GbE.
But its not working as I expected.

Is the 2nd NAS the same as the first NAS?
Is the 2nd Adapter the same as the first Adapter?
Which Thunderbolt port is the 2nd adapter connected to?

After testing all components I see that if I use only 1 Adapter it works - but whichever Adapter I connect second - that connection isnt working.

Define "not working". Does the adapter or NAS appear in the Thunderbolt or USB or PCI or Network tab of System Information.app?

 

[GoetzPhil]

Internet on iMac 192.168.0.xxx

Adapter 1) Thunderbolt Port 1 on iMac 192.168.25.100 connects to QNAP NAs directly at 192.168.25.101 - WORKS
Adapter 2) Thunderbolt Port on the old OWC Thunderbolt Hub with 3 T3 Ports 192.168.25.110 connects to Ugreen NAS at 192.168.25.111 - doesnt work when Adapter 1 is connected.

Like I said, I cross tested everything, changing adapters, ports and such - only 1 adpater at a time will work, as soon I connect the other adapter it is not working anymore.

 

[tonmischa]

192.168.25.110

This is probably your culprit.
Each adapter is creating its own network. You can not use the same IP Address Range (192.168.25.xxx) for both.

Set the second adapter to another subnet:
eg. 192.168.26.110 connecting to Ugreen NAS at 192.168.26.111.
(Subnet Mask for both adapters should be 255.255.255.0)

 

[joevt]

Internet on iMac 192.168.0.xxx

Adapter 1) Thunderbolt Port 1 on iMac 192.168.25.100 connects to QNAP NAs directly at 192.168.25.101 - WORKS
Adapter 2) Thunderbolt Port on the old OWC Thunderbolt Hub with 3 T3 Ports 192.168.25.110 connects to Ugreen NAS at 192.168.25.111 - doesnt work when Adapter 1 is connected.

Like I said, I cross tested everything, changing adapters, ports and such - only 1 adpater at a time will work, as soon I connect the other adapter it is not working anymore.

A hub with more than one downstream Thunderbolt ports is Thunderbolt 4 or Thunderbolt 5 but that doesn't matter for this issue.

This is probably your culprit.
Each adapter is creating its own network. You can not use the same IP Address Range (192.168.25.xxx) for both.

Set the second adapter to another subnet:
eg. 192.168.26.110 connecting to Ugreen NAS at 192.168.26.111.
(Subnet Mask for both adapters should be 255.255.255.0)

Is the Mac getting an IP address from the NAS for each adapter or is each NAS getting an IP address from the Mac? If it was the latter then I would expect the Mac to choose compatible IP addresses.
Or are the IP addresses assigned manually?

 

[GoetzPhil]

It works with the 26 subnet - thanks for the tip.

I decided to get the IOCREST Adapter at 95$ instead paying nearly 300$ for a 4port 10GbE Switch.
Sometimes money matters

 

[OWC_TAL]

This is probably your culprit.
Each adapter is creating its own network. You can not use the same IP Address Range (192.168.25.xxx) for both.

Set the second adapter to another subnet:
eg. 192.168.26.110 connecting to Ugreen NAS at 192.168.26.111.
(Subnet Mask for both adapters should be 255.255.255.0)

This would be my answer too. Great observation @tonmischa