modemmanager disconnects and not able to reestablish connection

[Chris Langhans]

Hi,

thanks for your response.

Network-manager is not installed. Thus I do not really know which
mechanism changes the IP settings when I call mmcli 
--simple-connect.
After looking through the logfiles I think the kernel driver 
(cdc_mbim
in my case) brings up the wwan0 device and dhcpcd takes care of 
changing
the IP settings. Correct me if I am wrong.

Here the corresponding section of the logfile:

Aug  1 03:25:16 raspberrypi systemd[1]: Started USB_ModeSwitch.
Aug  1 03:25:16 raspberrypi kernel: [   14.281840] usbcore: 
registered new interface driver cdc_ncm
Aug  1 03:25:16 raspberrypi kernel: [   14.285363] usbcore: 
registered new interface driver cdc_wdm
Aug  1 03:25:17 raspberrypi kernel: [   14.615873] cdc_mbim 
1-1.4:2.0: setting rx_max = 16384
Aug  1 03:25:17 raspberrypi kernel: [   14.615991] cdc_mbim 
1-1.4:2.0: NDP will be placed at end of frame for this device.
Aug  1 03:25:17 raspberrypi kernel: [   14.616799] cdc_mbim 
1-1.4:2.0: cdc-wdm0: USB WDM device
Aug  1 03:25:17 raspberrypi kernel: [   14.618650] cdc_mbim 
1-1.4:2.0 wwan0: register 'cdc_mbim' at usb-3f980000.usb-1.4, CDC 
MBIM, 8a:12:48:88:75:b3
Aug  1 03:25:17 raspberrypi kernel: [   14.619232] usbcore: 
registered new interface driver cdc_mbim
Aug  1 03:25:17 raspberrypi dhcpcd[483]: wwan0: adding address 
fe80::30bd:3fa9:a4be:97ae
Aug  1 03:25:17 raspberrypi avahi-daemon[465]: Joining mDNS 
multicast group on interface wwan0.IPv6 with address 
fe80::30bd:3fa9:a4be:97ae.
Aug  1 03:25:17 raspberrypi avahi-daemon[465]: New relevant 
interface wwan0.IPv6 for mDNS.
Aug  1 03:25:17 raspberrypi avahi-daemon[465]: Registering new 
address record for fe80::30bd:3fa9:a4be:97ae on wwan0.*.
Aug  1 03:25:17 raspberrypi dhcpcd[483]: wwan0: waiting for 
carrier
Aug  1 03:25:17 raspberrypi dhcpcd[483]: wwan0: carrier acquired
Aug  1 03:25:17 raspberrypi dhcpcd[483]: wwan0: IAID 48:88:75:b3
Aug  1 03:25:17 raspberrypi dhcpcd[483]: wwan0: rebinding lease of 
80.226.70.221

Thanks

Chris

Aleksander Morgado writes:

> Hey,
>
>>
>> I have a situation where my modem (Huawei K5160) is 
>> disconnected and I
>> can not reconnect to the network.
>> After disconnecting I tried to reconnect via simple-connect. It 
>> says it
>> reconnected correctly but e.g. I can not ping google.
>>
>> Maybe because it says:
>> uplink: '0' bps
>> downlink: '0' bps
>> but I do not know for sure.
>>
>> Does anyone know why it gets disconnected in the first place?
>>
>
> That looks like a network-initiated disconnection. We're 
> notified by
> the network of the disconnection and then it's up to us to 
> restart the
> reconnection.
>
> I see the new reconnection attempt succeeds in your logs, which 
> means
> that the only thing left to have proper connectivity would be to 
> setup
> the IP settings reported by the modem in the wwan network 
> interface.
> Are you manually doing that?
>
> Maybe you're also using NetworkManager along with ModemManager? 
> If
> that's the case you should reconnect using NM (e.g. via nmcli) 
> not
> with mmcli --simple-connect. NM will take care of configuring 
> the
> network interface in that case.