Static vs DHCP setups from ModemManager in OpenWrt

Peter Naulls peter at
Mon Jul 12 12:19:04 UTC 2021

Hello all.

I'm using ModemManger 1.16.6 on OpenWrt along with its scripts (and slight 
modifications so it doesn't just give up in the end).

After a lot of testing and loss of connectivity, it seems that although
our provider is offering DHCP, the connection via ModemManager is configured
statically. This leads to loss of connection after several hours unless
intervention is taken such as manual DHCP or re-configuring the interface.

We can see here:

# mmcli --modem 0 --bearer=1 --output-keyvalue | grep ipv4       : ipv4v6
bearer.ipv4-config.method       : static
bearer.ipv4-config.address      :
bearer.ipv4-config.prefix       : 29
bearer.ipv4-config.gateway      :
bearer.ipv4-config.dns.length   : 1
bearer.ipv4-config.dns.value[1] :
bearer.ipv4-config.mtu          : 1430

So the question is, is this a ModemManager bug? Or is it misreporting
from the carrier, or something else?  What can I do to debug this?


More information about the ModemManager-devel mailing list