Network problems with LTE modem in CDC NCM mode

D

DmitryVS

Good day! I'm trying to run the Fibocom L860-GL LTE modem on FreeBSD 14.1. This modem can work in CDC NCM mode. There is a script on the Internet that one good person wrote for this modem using PowerShell under Win and shared it. The essence of the script is quite simple: first, the modem is configured with a bunch of AT commands, IP settings are requested from the operator, then, according to them, the network interface and route are configured. I reproduced the essence of the script, but the connection does not work under FreeBSD. I tried the following steps in my system:

1. We configure the modem through its console:
> picocom /dev/cuaU2
Code: 
[a number of AT commands skipped here]
 AT+CGDATA=M-RAW_IP,1

OK

CONNECT
Here we got the modem connection on its CDC NCM interface. There we also requested $IP, $MASK, $GW

2. We configure the network interface:
> ifconfig ue0 inet $IP netmask $MASK
> ifconfig ue0
Code: 
ue0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        options=80000<LINKSTATE>
        ether 00:00:11:12:13:14
        inet 10.22.114.24 netmask 0xff000000 broadcast 10.255.255.255
        media: Ethernet autoselect
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

3. Set up the route:
> route add default $GW
> netstat -r4
Routing tables

Code: 
Internet:
Destination        Gateway            Flags     Netif Expire
default            10.22.114.25       UGS         ue0
10.0.0.0/8         link#4             U           ue0
10.22.114.24       link#3             UHS         lo0
localhost link#3 UH lo0

4. Checking what happenning. Now pings goes only to the $IP of the interface itself, and with some random delays. Other hosts are not available.

5. What I'm doing wrong? Please help.

PS: To check the functionality of the hardware, I used the following options: 1) Win10 with the original PowerShell script for setting up the modem as CDC NCM device; 2) ppp in FreeBSD for setting up the modem on its cuaU interface. Both options work. But I would like to have CDC NCM connection in FreeBSD. But how?
 
Phishfry said:
Break out the manual and I bet you have other modes.
Click to expand...
Phishfry, thank you for ideas!

Regarding AT+CGDATA= command options. I'm using option taken from the working PowerShell script. Also I read the thread from your message and found two more sources with the same option as mine. But I also check all available options for this command on practice and it was not successful with any of them.

Regarding ATG+USBMODE command. This command is not supported by the recent modem FW versions as mine...

So far as the modem working fine as a CDC NCM device in the same rig but under Win10 OS, my guess is something wrong with FreeBSD setup but not with modem configuration script. I have a "status: active" for ue0 interface after modem init commands and setting up the interface address and I put a default route in the table. This is all my knowledge how to set up a single interface network. Now I have "ping: sendto: no route to host" for any IP address except ue0 interface itself. May be I missing something around...
 
The problem is solved. It was necessary to add to the ARP table the gateway IP address with the same MAC as the interface IP has.
 
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