Network Adapters Losing Connectivity

[john_sherrod]

Anyone having issues with ethernet adapters losing network connectivity on Big Sur and Monterey? We’ve seen this a ton, and can’t find a real fix. Users on Catalina never had this issue, but once they upgrade many of them have chronic problems with the adapter losing network. But the Mac thinks it’s still connected so it never fails over to wifi. Unplugging the adapter and plugging it back in restores connection, but it’s a major annoyance.

[aparten]

I've seen it a few times on a Mac mini on Monterey with the built-in network adapter and only a reboot could fix it. Haven't seen much said about the issue or how to resolve it yet, unfortunately.

[john_sherrod]

Oh, interesting. We don't have a lot of Macs with built-in ethernet any more, but good to know there's weirdnesses there too.

[andrew_weaver]

Do you happen to use Crowdstrike? We also are running in to this and have done a little troubleshooting. One device had no issues until we installed the Crowdstrike sensor. Haven't confirmed it was the cause, but it might be a start.

[Tribruin]

We are seeing this way too much with Monterey. The worst case is that we are seeing this during deployment. In most cases, it happens right after we install Crowdstrike. Based on some discussions on the MacAdmins slack channels, it appears to be related to Network Filters (Crowdstrike and Cisco AnyConnect both have it. So I am doubly challenged.) 

I am also seeing it on existing computer. Right now, my computer is connected to a CalDigit TS3+ dock and I can't get an IP address. I am stuck on using WiFi. 

[john_sherrod]

We use Carbon Black Cloud, which does have a network filter system extension. But we're only seeing this with ethernet adapters, and I would think CB would be affecting the whole network stack, but who knows?

[Tribruin]

Everything I have seen is that it only affects wired networks. And, I suspect, only certain ethernet chipsets. I have had no issue with WiFi. It is a very strange bug. 

[PhilS]

When it bites my Macs it bites the whole network stack, nothing can connect until reboot. And I truly hate having to tell users this is a macOS bug, but we've seen it since our very first Big Sur installs.

We use Cybereason rather than CrowdStrike; Palo Alto GlobalProtect for VPN, and only the Umbrella component of AnyConnect (both of which do install network filters).

[TJ_Edgerly]

Is this only happening with Apple Silicon Macs or are you also seeing this on intels? Also, do you have the network filter enabled on these machines under System Preferences>>>Network?

[john_sherrod]

Mostly with Intel Macs, but that's probably because they're still the overwhelming majority of our Mac fleet. Carbon Black does use a network filter system extension.

[PhilS]

Saw it on Intels before the release of the first M1’s. And the network filters show in Network, enabled when the VPN connects.

[jhuls]

My 2021 Macbook Pro plugs into an OWC TB3 Dock to use ethernet when at my desk and I've not noticed this issue. Previously I had a 2018 Macbook Pro for the same use and did not notice this as well.

SentinelOne is installed on both systems.

[emptypony61]

This is a known issue I just have to uninstalled Carbon Black. 

Carbon Black Cloud: Network is Slow or Disconnects... - Carbon Black Community 

[john_sherrod]

I suspect that's what's causing out issue as well, though it's odd that it seems to affect some network adapters more than others. Unfortunately do to security policies I can't leave Carbon Black uninstalled. I did have one user recently who was having this issue chronically, and since I uninstalled and re-installed Carbon Black I haven't seen the issue return for him.

[emptypony61]

Did you do it manually or through Jamf?

[john_sherrod]

I have an uninstall Carbon Black policy I deploy through Jamf. Then flushed this particular Mac from my install policy to re-install it.