External USB Gigabit Ethernet Disconnects

Support & Help Requests Raspberry Pi
1

Hi all,

I’m having a problem with my Raspberry Pi 3 using an external USB Gigabit ethernet adaptor.

Every now and then the adaptor disconnects. I don’t know if it’s powering off or just being dropped by the kernel randomly or what.

The Pi runs Ubuntu Mate 16.04.2 LTS headless. The onboard ethernet is unplugged, wifi unused/unconfigured.

I’m not aware of any power management the Pi does; there’s no upowerd process running, and it’s only wifi that has the power management switch in /etc/network/interfaces as far as I know.

Any clues, hints, pointers?

Thanks

2

I don't know if TLP is installed on the RPi version, can you check?

apt-cache policy tlp

By the way, you can monitor hardware and driver events with:

tail -F /var/log/kern.log

3

root@Moya:~# apt-cache policy tlp
tlp:
Installed: 0.8-1
Candidate: 0.8-1
Version table:
*** 0.8-1 500
500 http://ports.ubuntu.com xenial/universe armhf Packages
100 /var/lib/dpkg/status

Looks like.

4

So I recommend you check that out, maybe something here:

5

Installed … but not used?

# Set to 0 to disable, 1 to enable TLP.
TLP_ENABLE=0

I’ve added a blacklist line anyway; can’t hurt, right?

Thanks

6

And that didn’t fix it. :frowning:

There’s nothing in kern.log about the connection going, just when I unplug it and plug it back in to fix it after it’s disconnected.

I’m going to try enabling TLP and see what happens.

7

Just to make sure because we didn’t ask you yet but when you say “it disconnects”, you mean you can’t ping outsite localhost right?

8

It’s a headless box - I cannot ping to it.

9

Here’s the latest thing I’ve found - the network switches off, but I don’t think it’s the USB NIC powering down. Unplugging the ethernet from the NIC and plugging it back in fixes it, so it’s what … dropping the DHCP and not asking for a new IP?

Is that something that NM should manage? Can I tweak that on the CLI? Otherwise I’d have to re-enable the GUI and VNC in.

10

That should be easy enough to test.
Get your interface name from ifconfig, then when the connection goes down use:

sudo dhclient name