I have an old small TP-Link TL-MR3020 V1 Travel Router with a ZTE MF833U1 USB LTE Stick. I know that these routers are to old and not recommended for Openwrt 18.06 or later in due to less memory 4MB / 32 MB RAM but this is ok for me. Installed firmware version 17.01.7 from this URL and the following packages:
LAN interface is configured with a static IP 192.168.100.1
LEDE WLAN AP interface is enabled and started.
opkg install kmod-usb-net-cdc-ether usb-modeswitch
and then I createed the following "lte" WAN interface
config interface 'lte'
option ifname 'usb0'
option proto 'dhcp'
option metric '100'
The USB LTE Stick is detected by the driver as eth1 interface. When I replug the stick in usb port and enable the lte interface it get's a 192.168.0.178 IP address with default route IP 192.168.0.1
Then I added the lte interface to the wan firewall zone.
Internet Access is available only to LEDE WLAN connected Clients. They get dhcp addresses from 192.168.0.0/24 Scope. I like to get internet access with the LAN interface too but it is in 192.168.100.0/24 network and cannot reach the default router (LTE USB Stick) on 192.168.0.1
I believe that I have the double NAT problem. How can I get Internet Access with WLAN connected Clients and for example, a notebook that is connected with a cable to the LAN port of the TL-MR3020 router ? Adding the LAN interface to the wan firewall zone is not an option because I lost access to the luci web interface on http://192.168.100.1 and have to go into recovery mode and reset the complete configuration with firstboot && reboot now.
Who can help ?