[Help] I need to use OpenWRT router in addition to the router provided by ISP

Hello! I have attached an image of what the network requirements are below :

Basically, I have a router provided by my ISP which has a connection for the fiber cable. But, I want to use a OpenWRT router (redmi ac2100) as my main router to which all my devices will connect to. I have a cable coming from a LAN port of the router provided by ISP to the WAN port of the OpenWRT router. The problem I'm having is when I restart the OpenWRT router, it says connected but no internet. I have asked a similar question before but I didn't get the result that I wanted. I have tried creating a dumb AP but the adblock and network usage plugin don't work with a dumb AP. So the dumb AP is not a viable solution for me. If anyone can help me with this issue, that will be great. Thank you.

The ideal solution would be to configure the ISP router to bridge mode (maybe you can do that yourself, perhaps you might have to ask your ISP - some ISPs refuse doing that), to avoid the double-NAT and get the WAN IP on your OpenWrt router's WAN port (that would also imply that the ISP router would only act as 'modem'/ media converter, so advanced features like FXS ports/ DECT or wireless would be lost).

If that isn't possible, make sure that your ISP router's LAN and your OpenWrt LAN IP subnets differ and don't overlap, otherwise routing is impeded.


Hello! Thanks for your reply. I tried contacting my ISP but they said that can't help me with this.
As for the second option, can you please let me know how I can make the ISP router's LAN and the OpenWrt LAN IP subnets different? I don't know much about networks.

That's not a very helpful ISP you have. Can you link us the router model or give us pointers to your ISP and package so we can see what the router is?

The router provided by the ISP is "Huawei EG8247H5". I'm from Pakistan and almost all ISPs here don't entertain such requests.

A cursory Google reveals that the device likely supports bridge mode. This result for example, which may or may not be the exact settings you need to use. See post #7. There are other instructions in other search results.