Select which interface is used to connect to a shared volume

[kirkster501]

Hi all,
I have my MAC studio connected to the general home network and Internet with wifi 6E. I also connect a 10G point to point link with static IP address to my NAS. This works OK. However, sometimes I find the MAC uses the 1G link and not the 10G link.

MAC 10.0.0.1 -------- 10.0.0.2 NAS [shared volumes]

So finder can "see" these drives via two ways - via a network search on the wifi (which shows up at DS1821 in the image below) and also on the 10G interface. The NAS also has a 1G interface connected to my general network for other reasons. I only need the 10G link for high speed file access from the MAC studio for editing directly on the NAS. I still want to be able to access the files from other computers on the NAS' 1G link.

How can I configure the MAC studio to only access the NAS volumes over the 10G link please? How would I turn off thew MAC studio from finding (and showing) the DS1821 as an option in finder?

Many thanks!

 

[svenmany]

A bit of a guess - I believe you would have to turn this off on your NAS; you would have to make it not discoverable via mDNS (i.e. bonjour) on that interface.

To be honest, I'm a little confused by the screenshot. 10.0.0.1 seems to be the 10G NAS ip address. But, just above the screenshot you are saying that 10.0.0.1 is the Mac's address. Sorry if I'm being dense.

 

[kirkster501]

Hi, thanks for your thoughts. Sorry - I've edited the post above to (hopefully) make more sense.
10.0.0.1 is the NAS over the 10G link and the NAS IP address is reported as the drive (10.0.0.1) in finder.

If I turned it off on the NAS that would mean the other computers on my network would not be able to see the drives over their 1G interfaces. I only want this to happen on the Studio with the direct P2P link to the NAS.

 

[svenmany]

If I turned it off on the NAS that would mean the other computers on my network would not be able to see the drives over their 1G interfaces. I only want this to happen on the Studio with the direct P2P link to the NAS.

Good point. I guess you want DS1821 to be discoverable (the DNS-SD piece of mDNS) by all your machines except for your Studio. That is, you want it to appear in the Finder sidebars of those other machines, even when not yet mounted.

I believe your requirement is - you want all reachable hosts to be discoverable across your network, with the one exception that you don't want DS1821 to be discoverable by your Studio. I certainly could imagine achieving this using the native packet filter on your Studio. Perhaps there is also some way to configure the Studio's mDNSResponder to do this, but I suspect Apple has this pretty locked down.

I hope someone else has better ideas.

 

[FreakinEurekan]

If you get a 10GB Ethernet switch, you should be able to hook everything up to that. The 1GB devices will only get a 1GB link, of course (you could even link in a 1GB Ethernet switch for all of those; you don’t need 10GB ports for EVERYTHING - just for 10GB items and items that might change to 10GB in the foreseeable future). That would let you just use the 10GB port on the NAS and the Mac, and just use the 1GB port everywhere else, and they should all talk to one another fine.

 

[kirkster501]

Thanks guys.
Yes Svenmany, that is exactly the situation and what I want to do.
I don’t really want to go for a 10G switch, not yet at any rate, because my only 10G requirement is between my Ultra Studio and the NAS.

 

[Bigwaff]

Why NAS need to be discoverable on 1G network if using static IP? Other clients could connect to shares using 1G static IP address without need mDNS enabled on NAS. Then Studio connect to two different IP addresses (1G address and 10G address) for shares. To Studio it would be like connecting to two different file share servers. Just thinking…

 

[svenmany]

My understanding is the NAS has two network interfaces. The one configured with the address 10.0.0.1 is connected directly to your Studio. The other interface is connected to some router or switch which your studio (via WiFi) and other devices have access to.

Unless you've taken steps to configure bonjour specially on your NAS, I suspect it's advertising the DS1821 name on both interfaces. It could be that the DS1821 name is actually resolving to 10.0.0.1 on the Studio machine. You can tell if you ping "DS1821.local". If that is the case, maybe your use of that name on the Studio is giving you the bandwidth you want already.

 

[Chancha]

IMO the OP is already setting the hardware and settings up ideally, in that the NAS broadcast itself to the main LAN with the DS1821.local domain (which is also the NAS gateway to the main router), and leave the 10G static LAN closed and exclusive to the Studio. This way all the normal internet and functions on the NAS that rely on network discovery will work normally without config.

Then the only odd one is the Studio. The OP already sees this problem, the Studio sees two paths to the NAS, one via the larger subnet domain while the other with the closed subnet of the 10G NIC. You want to do this, since the Studio will still need to access the rest of the network like it belongs. So the make do is on the user's burden, every time you want to make sure you access the NAS with the faster interface, you need to make sure you use the 10.0.0.1 IP and not accidentally the DS1821.local domain name. The only problem with this are apps that somehow doesn't let you point a static IP / address while insisting to find its target by itself, and end up using the 1G instead. Such as Time Machine on older macOS comes to mind.

It is possible to use 3rd party network apps on this Mac Studio to add a client side filter to snitch out that broadcast if you want but it is more trouble than its worth. Or if you have a enterprise / homelab class firewall you could do that as well, but if you did you wouldn't be asking here.

 

[kirkster501]

IMO the OP is already setting the hardware and settings up ideally, in that the NAS broadcast itself to the main LAN with the DS1821.local domain (which is also the NAS gateway to the main router), and leave the 10G static LAN closed and exclusive to the Studio. This way all the normal internet and functions on the NAS that rely on network discovery will work normally without config.

Then the only odd one is the Studio. The OP already sees this problem, the Studio sees two paths to the NAS, one via the larger subnet domain while the other with the closed subnet of the 10G NIC. You want to do this, since the Studio will still need to access the rest of the network like it belongs. So the make do is on the user's burden, every time you want to make sure you access the NAS with the faster interface, you need to make sure you use the 10.0.0.1 IP and not accidentally the DS1821.local domain name. The only problem with this are apps that somehow doesn't let you point a static IP / address while insisting to find its target by itself, and end up using the 1G instead. Such as Time Machine on older macOS comes to mind.

It is possible to use 3rd party network apps on this Mac Studio to add a client side filter to snitch out that broadcast if you want but it is more trouble than its worth. Or if you have a enterprise / homelab class firewall you could do that as well, but if you did you wouldn't be asking here.

@Chancha That is EXACTLY the situation.
On the NAS I put in a firewall rule block the SMB ports from the specific (static) IP address of the MAC Studio's 1G interface on the general LAN. But that doesn't work for some reason. I think the Studio is seeing the NAS from its L2 broadcast.
I am beginning to think the only way around this is a 10G switch.

 

[Chancha]

The above poster suspecting the domain being resolved to either 1G or 10G is the issue at hand. If your router is a generic consumer model, it likely does not have any custmoized control of resolving DNS. Then on your Studio side, one would ask, let's edit the UNIX host config file so that the DS1821.local can be dead set to 10.0.0.1 as well; the problem of doing so is that anything that was meant to only work on the 1G side from your NAS to your Studio just wouldn't work.

But then I think you have a lot of options here, the current situation isn't that bad. Say you end up getting the 10G switch, and fall back to only rely on the 10G port of the Studio for pretty much everything to the LAN, you still probably need to leave WiFi on to the same (1G LAN) for AirDrop/ continuity related Apple functions. At that point you will get another confusion just at a different place. I speak from experience here, my company / studio we deploy a 20G infra-structure, MacBooks connect to either Thunderbolt docks with 10G ports or 10G NIC TB dongles. But WiFi has to be left on since the laptops while undocked, they still need to access the LAN like normal, only slower. We frequently see cases where these laptops are already docked back, with both the 10G NIC and the 1G WiFi running, macOS and apps can still be confused as to which side to use; this can't be fixed with static IP since the 10G NICs are connecting to the wider LAN subnet, not like your case where the 10G is a closed subnet. So in fact your current hardware situation actually gives you more control as to when the Mac Studio does use the 10G, with that IP that is.

 

[svenmany]

IMO the OP is already setting the hardware and settings up ideally, in that the NAS broadcast itself to the main LAN with the DS1821.local domain

I'd like to confirm that. @kirkster501, did you configure the NAS to only broadcast the DS1821 name on one of its two interfaces?

Run

dns-sd -G v4 DS1821.local

If you see both ip addresses of the NAS, then the NAS is broadcasting the DS1821.local name on both interfaces.

Run

ping DS1821.local

If the result shows you are hitting 10.0.0.1, then the whole problem disappears.

It is possible to use 3rd party network apps on this Mac Studio to add a client side filter to snitch out that broadcast if you want but it is more trouble than its worth. Or if you have a enterprise / homelab class firewall you could do that as well, but if you did you wouldn't be asking here.

This is a triviality with the native packet filter already present on the Studio. DNS-SD responses from the NAS to the Studio's WiFi interface can easily be blocked. You just have to block UDP port 5353 traffic with source address of the NAS WiFi interface. The command line interface is pfctl. The man page will kill you, but the configuration for this requirement is trivial.