Jagra

i feel like i am setting the modem up wrong i dont know where to plug in each ethernet cable to have the internet provider router running and the netduma router running i couldnt access the OS. Bascially just asking how to set the ethernet cables correctly to have it running

Ive had it set up in the past and unplugged it but im now trying to get is setup again but no matter what ethernet combination i use i either dont have internet or cant acess the duma software and not recognized how do i set it up with my regular internet router