inseego/AT&T USB800 LTE Modem on Ubuntu 20.04

[ericpang]

Dear all,

I'm attempting to get this wireless usb modem to work on my Ubuntu 20.04 box.

However, upon plugging it in, looks like the Linux host cannot be properly initialize it. The User Manual for USB800 USB WAN indicates that it is Linux compatible, but I am getting the following error logs:

```
  kernel: [4627412.526593] usb 2-1.3: USB disconnect, device number 45
kernel: [4627412.526654] rndis_host 2-1.3:1.0 enx0015ff036177: unregister 'rndis_host' usb-0000:42:00.3-1.3, RNDIS device
kernel: [4627412.850617] usb 2-1.3: new high-speed USB device number 46 using xhci_hcd
kernel: [4627412.965436] usb 2-1.3: New USB device found, idVendor=1410, idProduct=b020, bcdDevice= 3.18
kernel: [4627412.965437] usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
kernel: [4627412.965438] usb 2-1.3: Product: USB800
kernel: [4627412.965439] usb 2-1.3: Manufacturer: Novatel Wireless
kernel: [4627412.965439] usb 2-1.3: SerialNumber: 0123456789ABCDEF
networkd-dispatcher[1394]: WARNING:Unknown index 164605 seen, reloading interface list
kernel: [4627413.051430] cdc_ether 2-1.3:1.0 eth0: register 'cdc_ether' at usb-0000:42:00.3-1.3, CDC Ethernet Device, 00:15:ff:03:61:77
kernel: [4627413.053699] hid-generic 0003B020.282E1: hiddev0,hidraw0: USB HID v1.01 Device [Novatel Wireless USB800] on usb-0000:42:00.3-1.3/input2
systemd-udevd[2240731]: Using default interface naming scheme 'v245'.
systemd-udevd[2240731]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
kernel: [4627413.057187] cdc_ether 2-1.3:1.0 enx0015ff036177: renamed from eth0
systemd-networkd[1266]: eth0: Interface name change detected, eth0 has been renamed to enx0015ff036177.
networkd-dispatcher[1394]: WARNING:Unknown index 164605 seen, reloading interface list
systemd-udevd[2240731]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
ModemManager[1515]: <info> [base-manager] couldn't check support for device '/sys/devices/pci0000:40/0000:40:08.1/0000:42:00.3/usb2/2-1/2-1.3': not supported by any plugin
```

Another strange symptom is that the associated network device 'enx0015ff036177' is disappearing from `ip link` results every 10 seconds or so.

The 'modem-manager' is also not seeing any plugged in devices here.

```
mmcli -L
No modems were found
```

What seems to be the problem here? Thank you in advance for your advice!

[Hogwild]

I suggest you take a look at the forums for usbmodeswitch. They know a lot over there about getting LTE dongles to work in Linux.

https://draisberghof.de/usb_modeswitch/

[pavelp23636]

Hi,
your modem is detected properly as a network card.
So you can activate it with NetworkManager (run DHCP client on it). Or manually run dhclient NET_LINK_NAME
There is no need to use ModemManager (mmcli) in your case.
While it disappears - check logs. journalctl -r