I have a huge problem configuring EM7455 with static ip.
I run it on a router WRT1900ACS with LEDE and modemmanager and Kernel 4.9.10.
I get LTE-connection with static IP but after some minutes the connection dies without any message in the log.
I tried it by qmi and mbim with modemmanager and mbim without modemmanager without any success.
It is always the same: Connection is lost after some minutes.
Some days before I had a dynamic public IP and everything was fine.
It is the same also with “OpenWRT chaoscalmer” and mbim: dynamic IP OK! static IP bad!
Now the SIM (provider A1) runs in Fritz!box 6820 LTE with static IP flawlessly since some days…
I’m having similar issues. I cant keep a connection using ModemManager in qmi or mbim but I can using the old modified mbim.sh and not using ModemManager. It goes down every 10 min with modemmanager. It seems to stay up longer when not using wifi for some reason. The strange part is it works fine on modemmanager in ubuntu.
Turn off ipv6 on your lan interface and see if that helps.
My problem is with an internet facing public ip it only works for a few seconds once 2 or more devices are attached to the router.
A natted ip works fine.
Only work around it have found is to run a vpn on the router. There has to be a better way.
There has to be some other issue then.
I run a EM7455 with a public IP (although dynamic) with no problems in MBIM mode. I use umbim and not the ModemManager.
I dont have problems with umbim either. But uqmi I do.
I have the same issues with libqmi.
If only one device is on it works fine. Once 2 or more devices connect it looses the bearer. UMbim doesn’t do this for some reason. I’m leaning towards an ipv6 request issue maybe. I dont know. But for some reason running a vpn solves the issue.
Would suggest to use MBIM then. You could use uqmi commands with the “-m” switch too, so you would not lose much there.