Hi, I am new to OpenWrt, been fiddling around with it a couple days now and I can't figure out how to do what I want to do. Please be patient with me, I don't know a lot about networking, I know just enough to be dangerous.
Anyway, downstairs from me there's a Huawei B818 4G+ modem/wireless router combo. I ran a cable from its LAN port up a floor and into the Internet port of a Netgear Nighthawk R8000 wireless router I flashed with OpenWrt. From its LAN port I then ran a cable to an unmanaged Zyxel switch in the room over, and from that switch into my computer. So that's the layout I have so far.
On the OpenWrt side I have configured the LAN interface to use a static 192.168.2.1 address, with 192.168.1.1 as the DNS and gateway address to the B818. That works when it comes to the wired connection to the unmanaged switch and to my computer, however it's not ideal.
What I really want is two things. One, I would like to not have to specify a static IP on my computer or any other computer connecting to the switch and then back to the OpenWrt router, so for that I would need DHCP, but since the OpenWrt router is getting its connection from the B818 I don't know if that's possible? One would think that the OpenWrt router could forward address requests to the B818 somehow and just relay the traffic between the Internet and the LAN port. But I have no idea how difficult that might be, or even if it's possible at all.
For the second thing, I actually want the OpenWrt router to work as a wireless router, relaying traffic to the B818 through its Internet port to the LAN port of the B818. Because the B818 signal isn't great upstairs, so I thought since I already have another decent router I could put it to use. No idea how feasible that would be either, that should ideally also just work without having to specify things on the end devices (phones, tablets etc).
So, is this realistically possible for a beginner like me or should I just give up and just remove the OpenWrt router and go directly from the B818 to the unmanaged switch and then DHCP will at least work for the wired client devices?