Trigger usb_modeswitch on boot for Huawei E3372 Modem

You don't need a firmware update, but you do need a modeswitch, which you've found, and a dialer, which you haven't found. The following config files, taken from NVDC Stuff Networking, Virtualization and Data Center Stuff may work out of the box. If not use each as a template and tweak until it starts working:

/etc/usb_modeswitch.conf

DefaultVendor=0x12d1
DefaultProduct=0x14fe

TargetVendor=  0x12d1
TargetProduct= 0x1506

MessageContent="55534243123456780000000000000011062000000100000000000000000000"

/etc/wvdial.conf

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0
Init3 = AT+CGDCONT=1,"IP","internet.t-mobile.cz"
Stupid Mode = 1
ISDN = 0
Modem Type = Analog Modem
New PPPD = yes
Phone = *99***#
Modem = /dev/gsmmodem
Username = { }
Password = { }
Baud = 9600

Usage

1. Create a link from /dev/gsmmodem to /dev/ttyUSB2, that is the modem.

2. Dial the outside world. Note that you must do this every time:

   wvdial >/dev/null 2>&1 &
   

3. Add the following to your system's local startup scripting area:

   MODEM_STORAGE="12d1:14fe"
   MODEM_MODEM="12d1:1506"
   
   # 0 = storage, 1= modem
   MODEM_MODE=0
   
   check_modem_mode () {
    echo -n "Checking modem presence... "
   
    lsusb | grep --quiet "$MODEM_STORAGE"
   
    if [ $? -eq 0 ]; then
     MODEM_MODE=0
     echo "OK: modem in mass storage mode"
    else
     lsusb | grep --quiet "$MODEM_MODEM"
     if [ $? -eq 0 ]; then
      MODEM_MODE=1
      echo "OK: modem in modem mode"
     else
      echo "ERROR: modem not found"
      exit 1
     fi
    fi
   }
   
   set_modem_mode () {
    while [ $MODEM_MODE -eq 0 ]
    do
     echo -n "Setting modem mode... "
     usb_modeswitch -s 15 -I -H -c /etc/usb_modeswitch.conf     >/dev/null 2>&1
     lsusb | grep --quiet "$MODEM_MODEM"
     if [ $? -eq 0 ]; then
      MODEM_MODE=1
      echo "OK"
     else
      echo "FAILED"
     fi
    done
   }
   

Explanation

As I explained in a previous post, a GSM Modem always has two or more parts, in this model's case 3 parts.

• A Storage area, akin to a USB Stick.
• A Wireless Ethernet Adapter for connecting multiple devices to it.
• A PPP Dialer, so that your wireless provider knows you're a paying customer, and can charge you for overages as necessary. Since you can prove you are a paying customer, because PPPoE requires authentication, you can use the negotiated IP Address to access the Internet.

Bullets 1 and 2 are controlled via the etc/modeswitch.conf config file. 12d1 is the Vendor MAC Address, so to speak. Using the local script, the rest of the MAC Address is created. 12:D1:14:FE, ends up as the storage device, and 12:D1:15:06 ends up being the modem. If not using the local script issue a usb_modeswitch -s 15 -I -H -c /etc/usb_modeswitch.conf

Note: By default, ie with no modeswitch Linux only sees the storage device, which is why the OP cannot see or use the PPP Dialer or the Wireless Device.

Once the modem is turned on using the modeswitch, wvdial, or one of it's many replacements, controls access to the outside world. With the modem in Modem Mode, you will finally see output similar to:

wwan0     Link encap:Ethernet  HWaddr 58:2c:80:13:93:13
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

ppp0      Link encap:Point-to-Point Protocol
          inet addr:10.83.249.176  P-t-P:10.64.64.64  Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:4265 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6699 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:506706 (494.8 KiB)  TX bytes:600991 (586.9 KiB)

when issuing ifconfig

I found a solution that works: https://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?f=3&t=3043&p=20026#p20054

/etc/udev/rules.d/40-huawei.rules:

# This is part of USB_ModeSwitch version 1.x.x
#
ACTION!="add", GOTO="modeswitch_rules_end"
SUBSYSTEM!="usb", GOTO="modeswitch_rules_end"

# All known install partitions are on interface 0
ATTRS{bInterfaceNumber}!="00", GOTO="modeswitch_rules_end"

# only storage class devices are handled; negative
# filtering here would exclude some quirky devices
ATTRS{bDeviceClass}=="e0", GOTO="modeswitch_rules_begin"
ATTRS{bInterfaceClass}=="e0", GOTO="modeswitch_rules_begin"
GOTO="modeswitch_rules_end"

LABEL="modeswitch_rules_begin"
# Huawei E3372-325
ATTRS{idVendor}=="3566", ATTRS{idProduct}=="2001", RUN+="/sbin/usb_modeswitch -v 3566 -p 2001 -W -R -w 400"
ATTRS{idVendor}=="3566", ATTRS{idProduct}=="2001", RUN+="/sbin/usb_modeswitch -v 3566 -p 2001 -W -R"

LABEL="modeswitch_rules_end"