Static vs DHCP setups from ModemManager in OpenWrt

Peter Naulls peter at
Thu Jul 15 15:43:04 UTC 2021

On 7/15/21 9:57 AM, Aleksander Morgado wrote:

>> After restart of ModemManager and then ifup wwan, reconnection is successful.
> Strange. What modem is this?

Sorry to add to the posts, but further testing shows another case where
this recovery didn't help. I don't have a good log of this, but it
appears that the ppp connection doesn't fully complete and pppd
times out.  In this case, we need to power cycle the modem - fortunately,
this is something that is easy to do for us (and previous testing
shows we need to power cycle the USB controller too), but of course
it leads to a lot of churn and connection taking time.

This would appear to be a bug with the modem. Obviously there isn't
much you can do about this, but I want to be clear about the different
cases we are dealing with.

Development wise, it seems like this is going to be a bunch of incremental
improvements to iron everything out.

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