Static vs DHCP setups from ModemManager in OpenWrt

[Aleksander Morgado]

Hey,

On Thu, Jul 15, 2021 at 3:39 PM Peter Naulls <peter at chocky.org> wrote:
>
> On 7/12/21 4:50 PM, Aleksander Morgado wrote:
> > you should ifdown & ifup the network interface
> > configured in netifd in order to reconnect.
>
> No such luck: (sorry for the wrap)
>
>
> hu Jul 15 13:31:11 2021 daemon.notice netifd: Interface 'wwan' is setting up now
> root at AWC-EI:~# Thu Jul 15 13:31:11 2021 daemon.notice netifd: wwan (2113): modem
> available at /org/freedesktop/ModemManager1/Modem/0
> Thu Jul 15 13:31:41 2021 daemon.notice netifd: wwan (2113): starting connection
> with apn 'firstnet-broadband'...
> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2113): error: couldn't
> connect the modem: 'GDBus.Error:org.freedesktop.ModemManager1.Error.Cor'
> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2677): stopping network
> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2677): IPv4 connection
> teardown required in interface wwan: static
> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2677): running
> disconnection (common)
> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2677): Command failed:
> Permission denied

I've seen this log in the past, I have no idea what it means. @Nick B any idea?

> Thu Jul 15 13:31:52 2021 daemon.notice netifd: wwan (2677): error: couldn't
> disconnect all bearers in the modem: 'GDBus.Error:org.freedesktop.Modem'
>
>
> As you mentioned, there's probably some logic missing here in OpenWrt. I'm
> guessing the only recovery here is to restart ModemManager.
>

You should never need to do that really. If the setup works again
after restarting MM, there may be some additional thing to fix
somewhere in MM itself.

> Here's some more debug if it helps:
>
> root at AWC-EI:~#  mmcli --modem 1 --bearer=1

You don't need the "--modem 1" part. Bearer IDs are unique across
modems as well, so just "mmcli --bearer 1" should be enough.

>    ------------------------------------
>    General            |           path: /org/freedesktop/ModemManager1/Bearer/1
>                       |           type: default
>    ------------------------------------
>    Status             |      connected: yes
>                       |      suspended: no
>                       |      interface: wwan0
>                       |     ip timeout: 20
>    ------------------------------------
>    Properties         |            apn: firstnet-broadband
>                       |        roaming: allowed
>                       |        ip type: ipv4v6
>    ------------------------------------
>    IPv4 configuration |         method: static
>                       |        address: 10.55.89.75
>                       |         prefix: 29
>                       |        gateway: 10.55.89.76
>                       |            dns: 107.112.229.135
>                       |            mtu: 1430
>
>
> Earlier, when it was running:
>
> Wed Jul 14 11:50:45 2021 daemon.notice netifd: wwan (6178): modem available at
> /org/freedesktop/ModemManager1/Modem/0
>
> Which looks like the modem here moved from 0 to 1 (I don't know how the number
> allocation happens)

That could be an indication that the modem crashed and self-reseted.

>
> After restart of ModemManager and then ifup wwan, reconnection is successful.
>

Strange. What modem is this?

-- 
Aleksander
https://aleksander.es