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That seems reasonable. I'd go for the MS-01.

Or you can check out things like private VLANs or port isolation.

But the IP standard assumes that devices in the same subnet can communicate with each other via layer 2.

I-226V works very well for me.

It works when Router Advertisements are set to unmanaged.

I'm fairly sure hat DHCPv6 can not advertise more than one address range.

Für einen einzelnen managed Switch mit Web UI bin ich persönlich ein Fan vom Mikrotik CRS326-24G-2S+IN/RM - den gibt es als Tisch/Regalmodell (IN) oder rackmount (RM).

Aber als Einsteiger würde ich von Mikrotik dringend abraten, die Konfig ist ja nicht wirklich einfach zu verstehen.
Da wäre Unifi doch eher die bessere Wahl.

Mikrotik Switches mit SwitchOS drauf sind sehr vernünftig bedienbar. Von RouterOS auf dem Switch würde ich abraten, aber deswegen lassen die sich ja auf switchos umstellen.

VMWare support?

SR-IOV should have the same impact on the VM functionality as passing through the card, so I'm not sure if that is going to help you.

If you only want to reach the matter devices, you might want to go for "Static IPv6" and use a unique local address range (fdXX::).

Or zerotier.

[...]
@pfry: you can not trigger on NMEA, because PPS is its own line on the serial interface and only that line carries that signal.
[...]

Implementation dependent. Current RS-232 and USB implementations may have issues, but the old discrete UARTs could be configured to interrupt immediately on any signal. In addition, GPS receiver implementation will likely not support precise timing of NMEA data, but some old ('90s) units did have this option. I recall one in particular with its PPS optionally connected to DCD and normally disabled, as its normal RS-422 didn't have control lines. I'll have to plug in my old Ultralink WWV clock and see how bad it is now, as it uses a similar method (time delivered on the second, with PPS disconnected). It used to be quite accurate back in the day.

That is also what I have seen, that PPS is connected to DCD, but I do not know of any way to do precise NMEA timing without PPS.

I'll consolidate my answers into one post :) .

@Patrick: That's very cool, I have been looking for something cheaper than Meinberg.

@Greg_E: PTP is a whole different thing, I don't think we need that, we're just at NTP here.
Also, GPS has 2 time signals:
- coarse time is delivered via NMEA, but it pretty much only tells you the second. I have seen GPS time sources only using NMEA, even in the NTP Pool, but it's very bad practice
- precise time is delivered as a 1PPS signal, meaning one pulse per second, which triggers a pulse exactly on the second
A GPS time source as we know it uses a combination of both.

@pfry: you can not trigger on NMEA, because PPS is its own line on the serial interface and only that line carries that signal.

@lilsense: as long as your GPS interface maintains sync, it doesn't really matter which one you use. I recommend multi-band ones since they tend to hold sync better, especially indoors.

Those centerclick devices seem the way to go, they're pretty cheap for what they claim to do. If I had known that, I don't think I would have built my own esp32 based GPS stratum 1 NTP clock.

IMO GPS without PPS is not worth it. Better to use internet time.

IPv6 kommt, Widerstand ist zwecklos.

Ich nehme mal an, das lief via mdns und link-local Adressen.

Generally you need a serial gps adapter with PPS signal. GPS NTP performance without PPS is poor. Unfortunately I am not aware of USB GPS adapters that do PPS - probably because PPS is usually a dedicated line and maybe USB performance is not good enough for PPS anyway.

Unfortunately, I did not see that one.