Update 11.3.1 USB ethernet randomly disconnects

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Update 11.3.1 USB ethernet randomly disconnects

I recently updated my Macbook Pro to 11.3.1 and ever since then my USB Ethernet adapter stops working at any time. It had been working as expected in all prior versions.

I found a temporary solution is to turn off "USB 10/100/1000 LAN" interface in network prefpanel, then back on. The ethernet may work for a minute or an hour, no telling which. System Profiler shows the device plugged into USB:

 Vendor ID:	0x0bda  (Realtek Semiconductor Corp.)

I get this readout from Terminal:

system_profiler SPEthernetDataType
Ethernet Cards:

    USB 10/100/1000 LAN:

      Type: USB
      BSD name: en7
      Kext name: com.apple.DriverKit.AppleUserECM.dext
      Location: /System/Library/DriverExtensions/com.apple.DriverKit.AppleUserECM.dext
      Version: 1
      MAC Address: 00:00:ba:60:ed:42
      Product ID: 33107
      Vendor ID: 3034

    Apple 57761-B0:

      Name: ethernet
      Type: Ethernet Controller
      Bus: PCI
      Vendor ID: 0x14e4
      Device ID: 0x16b0
      Subsystem Vendor ID: 0x106b
      Subsystem ID: 0x00f1
      Revision ID: 0x0010
      Link Width: x1
      BSD name: en4
      Kext name: AppleBCM5701Ethernet.kext
      Firmware version: 57761-a1.54
      Location: /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/AppleBCM5701Ethernet.kext
      mDNS offload capable: 38:c9:86:0a:e4:78
      Version: 11.0.0

Can this be a problem of colliding drivers? Any fix for this problem?

Posted on May 17, 2021 6:28 AM

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Answer 1

May 31, 2021 8:22 AM in response to Gnarlodious

I have this same issue with two different Realtec RTL8153-based USB3 Ethernet adapters, one from the Best Buy brand Insignia, and another from Amazon Basics (Amazon Basics has made several versions over the years with different chipsets, this one happens to have the RTL8153). However, the 13" MBP M1 that I'm having this issue on is still running macOS 11.0.1.

I just started using this laptop and tried the two adapters I had laying around, so there was not a time that it worked correctly for me, I just found this post searching for a solution.

For what it's worth, my CalDigit TS3 dock with an Intel network controller does not have this issue - it is rock-solid.

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Answer 2

Gnarlodious Author

Level 4

3,293 points

May 31, 2021 9:48 AM in response to tchadrogers

I'm pretty sure what causes this is that RF (Radio Frequency) gets into the ethernet cable and shuts down the adapter. I found that once it happens, I have a setting in Network prefpanel to shut off all interfaces. When I turn it back on, it will work again for a while.

Keep in mind that RF energy emits from an antenna in a perpendicular direction. Your ethernet cable should be directly above or below the dongle to minimize RF interference. I also have had good luck using as short as possible ethernet cable (18"), since the USB side is not subject to the same interference. Also, I first used a very flat flexible cable but found that these are not suitable. The reason is that the large round cables have spiral wound wires inside (“twisted pair”), a method that minimizes RF interference. The thin flat cables do not, so they are more susceptible.

Hope this helps.

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Answer 3

Gnarlodious Author

Level 4

3,293 points

May 17, 2021 11:31 AM in response to Gnarlodious

I switched to the Thunderbolt Ethernet adapter and it still happens.

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Answer 4

May 31, 2021 8:22 AM in response to tchadrogers

removed

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Update 11.3.1 USB ethernet randomly disconnects

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