The Netgear Unite AC770s is a 4G LTE modem using qmi. To use it with OpenWRT follow the guide in the docs.
Upon completation of steps in the guide, you might notice that there's an IP Address from DHCP but no internet connection. The device uses raw-ip and the qmi scripts on OpenWRT doesn't set this mode correctly.
You need to modify the qmi.sh script in /lib/netifd/proto/qmi.sh (github)
original
uqmi -s -d "$device" --set-data-format 802.3 > /dev/null 2>&1
uqmi -s -d "$device" --wda-set-data-format 802.3 > /dev/null 2>&1
dataformat="$(uqmi -s -d "$device" --wda-get-data-format)"
if [ "$dataformat" = '"raw-ip"' ]; then
...
change it to
#prevent setting up the data format
#uqmi -s -d "$device" --set-data-format 802.3 > /dev/null 2>&1
#uqmi -s -d "$device" --wda-set-data-format 802.3 > /dev/null 2>&1
#dataformat="$(uqmi -s -d "$device" --wda-get-data-format)"
#make it true for the next if block
dataformat='"raw-ip"'
if [ "$dataformat" = '"raw-ip"' ]; then
...
Reboot your OpenWRT router and the device now obtains an IP Address and it has internet connectivity.
Log in with SSH and test it using the command
ping google.com -I wwan0
wwan0 is the network interface for your modem.