Daisy-chaining routers?

[Arthur_D]

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?

Thanks.

[bill888]

Have you disabled the DHCP server on Openwrt router? You should not need to set static IP addressses on devices wired to R8000 LAN port if the DHCP server is working.

If it is not working properly, for simplicity, factory reset the R8000 using LuCI > System > Backup/Flash firmware > Perform Reset. Unplug the WAN cable to R8000. Upon reboot, log in and configure LAN IP address 192.168.2.1 only. Now plug WAN cable into R8000. Devices wired to R8000 LAN ports should pick up DHCP IP address from R8000 and have access to internet via your B818.

Be warned that broadcom devices like R8000 are not fully supported in OpenWrt. Possible wifi driver issues. Consider using original Netgear firmware, DDwrt or Tomato if you have wifi issues.

[eduperez]

What you need is to configure the WRT3200ACM as a "dumb access point". There is a guide on the wiki specific for this scenario.

[Arthur_D]

Thanks a lot for your help! Looks like I overcomplicated things, and I ended up just flashing the original firmware back on again and let it do its thing, and it worked! OpenWrt seemed to either have a bit of an issue with the wireless as you said, or maybe I just misunderstood things - which we have established is quite possible.

Thank you both for replying, and sorry for my late reply. It's all solved now.

[bill888]

fwiw, R8000 OEM firmware appears to offer AP (Access Point) mode as an alternative to daisy chaining two 'routers'.

Daisy chaining routers creates an undesirable 'double-NAT' firewall issue. TBH, for a lot of users, this may not an issue.

[Arthur_D]

Thanks, I might give that a try. I may try to host a Minecraft server so I suppose double NAT may be troublesome in that case. Would AP mode and DynDNS in combination work for such a purpose and be reasonably secure?

[bill888]

TBH, I don't know whether DDNS is available and functions correctly when AP mode is enabled on R8000. On other routers, DDNS might only work if it is the primary ISP facing 'router'.