Ethernet adapter for M1 Mac

What are people using to connect their new M1 laptops to an ethernet network? I tried the Belkin USB-C to Gigabit Ethernet adapter cable (F2CU040) on the latest M1 14" Macbook Pro. However, I only get max 100 Mbps download speed. My network is 400-500 Mbps and I am getting close to those speeds on Wifi. I played around with the network settings but the adapter always seems to default to 100 Mbps. Has anyone found an adapter that actually works as advertised? Is this a Monterey issue?

That Belkin should work fine (I have one myself.) Double-check your cabling, you might have a bad ethernet cable that is forcing your Mac or switch to negotiate downspeed.

I’ve used 3-4 different adapters now with my M1, including a Caldigit 10GbE adapter, a Caldigit dock, a Cable Matters 2.5GbE adapter, a Satechi USB Dongle, and the Belkin. No issues, just using the built-in drivers.


I know the Ethernet cable is good since I get the expected speed on an older MacBook Pro that has an Ethernet port. So it seems my Belkin adapter is defective.

Using this inexpensive Gigabit dongle that I have tethered to my CalDigit TB4 hub at work. Plug and play, zero fuss. Works like a charm.

The cable itself can make a big difference. Make sure you’re using CAT6 cables, not the normal CAT5 or CAT5e. CAT5 and 5e are limited to 100Mbps and 125Mbps speed, whereas CAT6 is 1Gbps minimum and up to 10Gbps if it’s CAT6a. You may also want to make sure you have “shielded” cables - which helps prevent interference.

That being said, 400-500Mbps isn’t even gigabit speed, so the dongle and cables aren’t going to boost that speed, but perhaps get you closer to the 400-500 Mbps speed you’re looking for.

Here’s more about ethernet cables, for anyone interested.

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None of that is correct, there are multiple errors in that article; in at least one place, it may be confusing 125Mb (megabit) and 125MB (megabyte), 125 megabytes equals 1000 megabits.

Cat5 is sufficient for 1000Base-T (1 gigabit) up to 100 meters but Cat5e is more commonly used.
Cat5e and Cat6 are sufficient for 2.5GBase-T and 5GBase-T (2.5 & 5 gigabit) up to 100 meters, respectively.
Cat6a is required for 10GBase-T (10 gigabit) up to 100 meters but Cat6 is sufficient for shorter distances, up to 55 meters.

The networking standards have requirements not only for cabling but how the cabling is installed, how small a turn radius can be, but that’s generally not a concern for gigabit and lower.


Off-topic, but related to the recent discussion of cables.

I was (and still am) having problems with my internet. Too frequently, there is a 10 to 50 second delay (usually nearer the lower end) between when I tell my browser (which is what I use most) to open a web page (usually in a new tab) and when the browser actually shows anything. This is a major first-world problem, as you can imagine. Waiting 15 or 20 seconds five or six times per day? The horror.

Here’s the punchline. During a recent visit, the tech replaced my two end-to-end coupled factory-made cat 5 cables with an about 45 foot long cat 6 cable that he made on the spot. This is for my 50 mbps service. Yes, that’s 50 megabits per second, not 50 megabytes per second. The coupled cables would routinely deliver the 50 mbps (occasionally after a delay in starting), but the tech thought he would replace my setup “just in case.” As far as I can tell, it didn’t hurt anything. But it didn’t help.

There could be many different reasons. In the absence of any other information, I would start by checking:

  • DNS servers. If your primary DNS server is unavailable or acting flaky, then you might be seeing timeouts while your browser waits for a response, fails to get one, and then tries your secondary server.

    If you’re running your own DNS server, try using the one your ISP provides. If you’re using your ISP’s server, try using a third-party one like Cloudflare ( or Google ( If this works, you can investigate further to figure out why your previous configuration isn’t working.

  • See if your router has any kind of “intrusion detection” features you can turn off or reconfigure. Some are not implemented very well and can see your own normal browser traffic as an attack, killing connections. I blogged about this in 2014.

  • If you’re using any kind of firewall software or hardware, it may be configured to be overly aggressive, blocking legitimate traffic along with potentially malicious traffic.

I’m not surprised, but it’s a cheap and easy test, “just in case”.


Often such issues are related to DNS config or your local wifi.

That said, ever since Monterey and my new 14" MBP, I’ve been seeing such an issue with Safari. And I know it’s neither DNS nor a specific wifi. I can replicate it on a vanilla Monterey install. I observe it on various wifi networks including both at work (campus wide wifi, non-Apple, and usually very good) as well as at home (latest AirPort Extreme hooked up to Gigabit fiber, excellent performance before Monterey with both Intel and M1-based Macs, incl. two 2020 models). The reason I also know it’s a Safari issue rather than something on the network is that I usually can get Safari to start loading the page, if I launch any other browser on my Mac and have it open the page Safari is struggling with (the other browser so far never struggled loading that page). A Safari restart will also often (but not always) fix the issue. The issue shows sporadicly, it’s hard to pin point exactly when or with which pages it occurs—although there’s one specific work site I use that often suffers from the issue. It must nevertheless have something to do with wifi though because it never seems to show up when I’m connected through Gigabit (when working at the desk, hooked up to a TB4 dock equipped with a USBC-Gigabit adapter), it only shows when connected over wifi exclusively.

I had hopes that 12.1 might fix it, but no mention in the release notes and so far from what I can tell no difference. :frowning:

If you have any Safari extensions installed, try temporarily disabling them to see if anything changes. A flaky or overly-aggressive content blocker could be causing this.

It might also be a bug in Safari’s built-in security features, mis-identifying legitimate sites as malicious and therefore blocking them (or pieces of them, like some required script).

That’s a good suggestion, but unfortunately, it also happens when Ka-Block! is disabled (my only extension).

At this point I have to assume it’s a Safari bug. It’s just odd that so far it has never showed up when connected through Gigabit.

Thanks, @Shamino and @Simon.

Those are both in the list; first in the list is 2606:4700:4700::1111, which I believe is Cloudfare’s IPv6 DNS (if I correctly recall the TidBITS article that steered me to Cloudfare).

Not that I know about. It’s a tp-link Archer AX-50, about four months old, that I bought because the ISP said my Apple AirPort Express was likely the reason for the occasional lags. I changed little other than the default password, although I don’t recall what else I might have changed.

I was just poking around the web interface to the router and I see that it lists a Primary and Secondary DNS, neither of which is in my list of DNS Servers in Preferences > Network >Advanced > DNS. My guess is that the router got them from the ISP.

Certainly no dedicated hardware. The macOS firewall is turned on in Preferences > Security & Privacy > Firewall. The router’s firewall page says SPI Firewall is enabled, WAN Port pings are disabled, and LAN Port pings are enabled. There are no other firewalls as far as I know.