What is the reason for USB Network Interface going offline?

[prxmoxusr]

Aware that there can be a myriad reason, but just want check if there is anything in Proxmox v8.2.4 which can be tweaked to avoid behaviour. But, noticed this morning that eth1 (both eth1 and eth2 are UGREEN USB C 2.5G LAN Adapter Ethernet Adapter RJ45 2500Mbps Network Adapter) had gone offline (indicated not active) when checking Proxmox network. Not sure why it happened but did also change the autostart for the network devices to autostart. And to be honest I haven't been using neither of eth1 and eth2 since I've had problems getting the vlans to run proper (ref. to this thread).

For now I've try to bring the interface back with sudo ip link set enx6c1ff704695a up which didn't do the trick so tried with sudo systemctl restart networking which didn't worked either, so did a reboot. Which brought the eth2 back online again. [Correcting myself here seems that my eth2 is still down and won't go online again for whatever reason and now shows no active in the Proxmox GUI but sudo systemctl restart networking did the trick to bring back online again.]

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp88s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP mode DEFAULT group default qlen 1000 link/ether 48:##:##:##:##:3d brd ff:ff:ff:ff:ff:ff
3: enx6c1ff7046396: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr1 state UP mode DEFAULT group default qlen 1000 link/ether 6c:##:##:##:##:96 brd ff:ff:ff:ff:ff:ff
4: enx6c1ff704695a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master vmbr2 state UP mode DEFAULT group default qlen 1000 link/ether 6c:##:##:##:##:5a brd ff:ff:ff:ff:ff:ff
5: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 48:##:##:##:##:3d brd ff:ff:ff:ff:ff:ff
6: vmbr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 6c:##:##:##:##:96 brd ff:ff:ff:ff:ff:ff
7: vmbr2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether 6c:##:##:##:##:5a brd ff:ff:ff:ff:ff:ff

And the current interface config looks like this:

auto lo
iface lo inet loopback

auto enp88s0
iface enp88s0 inet manual
#Eth01: Intel I225-LM (2.5GbE)

auto enx6c1ff7046396
iface enx6c1ff7046396 inet manual
#Eth02: Realtek RTL8156BG (2.5GbE)

auto enx6c1ff704695a
iface enx6c1ff704695a inet manual
#Eth03: Realtek RTL8156BG (2.5GbE)

auto vmbr0
iface vmbr0 inet static
        address 192.168.202.10/24
        gateway 192.168.202.254
        bridge-ports enp88s0
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

auto vmbr1
iface vmbr1 inet static
        address 10.46.200.10/24
        bridge-ports enx6c1ff7046396
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

auto vmbr2
iface vmbr2 inet static
        address 10.46.210.10/24
        bridge-ports enx6c1ff704695a
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

 

[prxmoxusr]

As part of trying to mitigate potential USB autosuspend I've tweaked the proxmox host system with the following:

1. Added a new udev rule /etc/udev/rules.d/99-usb-ugreen-nic-autosuspend.rules with the following ACTION=="add", SUBSYSTEM=="usb", ATTR{idVendor}=="0bda", ATTR{idProduct}=="8156", TEST=="power/control", ATTR{power/control}="on"

and

2. Added the following usbcore.autosuspend=-1 to GRUB_CMDLINE_LINUX_DEFAULT (/etc/default/grub) in the hope of that it the NIC's won't suspend/disable again.

 

[prxmoxusr]

Well, this afternoon I noticed that the vlans assigned to eth1 and eth2 which utilise the usb network nic wasn't available and checking Proxmox network settings it should both nic active including that activity led was blinking and neither of them was particular wam. The vland which is assigned to eth0 worked fine; so it seems that it's particular the vlans assigned to the usb nics which cause headache.

Whether this is usb nic issue, rlt driver issue, proxmox or even switch issue doesn't help out here. Any suggestion anyone?

 

[prxmoxusr]

It's clear that it's the UGreen devices that have a tendency to drop offline; while the secundary one has stayed offline, the primary seems to drop off and on based on the uptime. Support case opened with UGreen to ask for help how to keep them online.