Getting NAS and iMac defaulting to 10gbe (actually 2.5)

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Getting NAS and iMac defaulting to 10gbe (actually 2.5)

Operating system
  1. macOS
  2. Windows
Mobile operating system
  1. iOS
This is for a direct connect from DS1621+ to iMac

I have a Synology DS1621+.
I purchased a 10 GbE card off ebay (here).
I also purchased a 2.5 GbE to Thunderbolt port adapter off Amazon.

I installed the 10 GbE card into my DS1621+. I ran a CAT 6 ethernet cord from the card over to the 2.5 GbE adapter and plugged it into one of my iMac Thunderbolt ports.

I used Will's video on SpaceRex to setup my NAS-to-iMac direct connection (Setting up a 10GbE Synology WITHOUT a 10GbE Switch on Synology NAS).

Here's the LAN setup on the DS1621+.

Screenshot 2023-10-20 at 9.20.35 AM.png

When I went looking for another Ethernet network item to use on the iMac, but I only found the one that the Mac is presently using to connect to my xFinity cable modem.

I wasn't sure what else to use, so I used an inactive service I found labeled "USB 10/100/1G/2.5G LAN" (since my connection is to a 2.5 adapter that sounded about right. LoL)

QUESTION: Am I correct in assuming these other "services" are created by various peripherals, and it doesn't matter much what you pick as it does how you configure it? Or, do I specifically need to use of the "Thunderbolt" services? If so, which one?.

Screenshot 2023-10-19 at 3.31.12 PM.png

Here's how I configured the item in iMac Network services to make the connection between Thunderbolt port with 2.5 Gb adapter and the 10 Gb card on the NAS.
Screenshot 2023-10-20 at 9.17.45 AM.png

I was able to log into on DSM from my browser so it appears that connection is live. ;)

QUESTION: I ran Blackmagic against a folder on the NAS IP and I got around 100 MB/s for write, and 99 MB/s for read. That doesn't seem right to me. Shouldn't it be significantly higher? What should I expect to see?

Please inform me of all my mistakes with liberal doses of salt! LoL


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The direct connection between Mac and NAS has to be used when mounting the NAS's shared folders in Finder. So don't use the ones that Finder has already found. Instead, to be sure, use Finder's Go menu and select Connect to Server. Then use smb:// . This should get the list of shared folders via the 2.5 to 10 GbE connection.

The Mac prioritises the active interfaces that it will use in list order, top to bottom. So you have to specifically use the local IP address of the direct connection in order for the Mac to know you want to route the connection that way.
Okay, just to throw a wrench in the works - I just hooked up a Netgear switch.
Green Cat 6 with two lights goes to DS1621+ 10 Gb card.
Green Cat 6 with one light goes to 2.5 Gb adapter and plugs into iMac Thunderbolt port.
Black Cat 5 with two lights goes to xFinity modem.
Blue Cat 5 with two lights goes to iMac Ethernet port.
Also, I TURNED OFF the WiFi on my iMac

After everything settled down and my iMac found the cable modem again, I found that my Blackmagic speeds had improved for the Thunderbolt-to-2.5 Gb-to-10 Gb card connection.

BlackMagic Stats
Write: 185.0 MB/s
Read: 169.5 MB/s

So that's good right? Shouldn't it still be faster though? Shouldn't "Read" always be faster than "Write?"
With the switch you could just make the NAS 10 GbE the default interface taking over from builtin interface you were using. Likewise, on the Mac you can change the service order and put the 2.5 GbE at the top of the list, plus configure it like the builtin interface. So now you don't have to manually configure the connection.

You got faster data transfer, as for should it be 2.5x more that before is difficult to say yes or no. There are other disk activities that your NAS can be doing which can have an impact. There are the two M.2 slots for read/write caching, but that's another guess if it will improve things significantly for the outlay.
Confused by "just make the NAS 10 GbE the default interface taking over from builtin interface you were using." What does that mean - what actions would I take?

Same on comment on Mac, "plus configure it like the builtin interface." Not sure what that means. What actions would be necessary?

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I got my NAS connected through the switch to the iMac via the Thunderbolt port. That's good.

But, now I'm having trouble with getting to the Internet. Not via my normal browsers (Firefox, Brave, etc.). But, the DSM control panel for my NAS is not getting connections to the Internet to do updates and stuff. That also means family cannot get to my photo albums that I've told them all about. Help?

Here's what I'm seeing...

Screenshot 2023-10-20 at 4.57.24 PM.png

Screenshot 2023-10-20 at 4.38.22 PM.png

Screenshot 2023-10-20 at 5.20.42 PM.png

Looks like even though the Mac is saying it has an ethernet connection, that DSM is not seeing that.

Below is the Ethernet service that would normally go to my cable modem. It seems to be saying all is good. And I do find my Web pages for normal sites loading fine. It's just the NAS DSM panel is not seeing the Internet now. I think that LAN 1 in Network Interface should be showing Connected, right?

Screenshot 2023-10-20 at 5.21.42 PM.png

Below is the service I'm using for the Mac-to-NAS 2.5 Gb connection. That seems to be working fine.
Screenshot 2023-10-20 at 5.22.36 PM.png
I would keep MTU (and other settings) default at 1500 for the moment, as non standard or differing settings on devices may disturb communication.
first get it stable, then optimize.
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Confused by "just make the NAS 10 GbE the default interface taking over from builtin interface you were using." What does that mean - what actions would I take?
Referring to the direct message: use Control Panel / Network / Network Interfaces / Manage -> Service Order to put the 10 GbE interface at the top.

But I didn’t realise that you had used an unmanaged switch to run two separate subnets: when you posted the photo I assumed you had all devices configured to use the same LAN subnet. I would just configure the 10 GbE interface to be on the home LAN The default gateway would be the router’s LAN IP, and probably so is the DNS server.

In the DSM widget you can change the LAN port being shown using the V arrow to its right.

[I see from the screenshot that there is no other LAN connection on the NAS so you had it trying to access the Internet through the Mac. Except the gateway IP on the NAS wasn’t set to the Mac’s IP. Nor, I suspect, do you have Internet Sharing enable on the Mac: even if you did this wouldn’t really work to allow other devices to access the NAS services.]

Same on comment on Mac, "plus configure it like the builtin interface." Not sure what that means. What actions would be necessary?
I would then configure the Mac’s 2.5 GbE interface to be on the home LAN, and move it to the top of the service list in Mac’s Network settings (using the ‘…v’ button on the bottom of the Network page and select Set Service Order).

Open the network settings for the built in 1 GbE interface and noted them down. Then open the network settings for the 2.5 GbE interface and use these settings. It will get a different IP address on the home LAN.

So now everything should be on the home LAN.

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