I have a raspberry pi 4 running as a purely wired router and a Zyxel multi m1 router running as a dumb AP.
Unfortunately I had to move and now I’m a situation where I have to connect my network to another via WiFi. At this moment I have tried to connect the dumb AP to the wireless network, however this does not make the internet available to the whole network. Do I have to bridge it somehow? Any ideas on what I can try?
You'll want to setup a wifi client router. As noted by @brada4, the wifi performance on the Pi is terrible, so it's not a great candidate for this method. It should be functional, but will be low performance.
If your Zyxel is running OpenWrt, you can make that your router per the above link and you should get reasonable performance. If it's not currently using OpenWrt, you should consider that as an option:
@psherman I do have it running openwrt, so I can make it run as a router and have it working, however won’t I lose performance doing this?
My hope would be to maintain the same topology, but I’m guessing there’s no way for the dumb AP (running openwrt) to connect to the wireless and forward that connection to the router (raspberry pi 4).
In theory, yes. Your radio could suffer as much as a 50% hit insofar as it has to operate in both STA and AP modes simultaneously. However, in practice, no, I don't think so. This is because I suspect that the bandwidth of the wifi uplink will actually be the limiting factor, and the ZyXel is not a bad device in terms of the routing performance capabilities.
The only way to know is to test -- fairly easy to do. Make a backup of your current config so you can easily restore back if/when needed, but then you can reset to defaults and setup the wireless client mode operation.
No, when running sta mode, there is no easy method to bridge to ethernet for the topology you're interested in. And, even if that was practical physically, I think it wouldn't give you any performance advantage over the standard wireless client routed mode that I'm recommending.
What @mk24 said is true. However, ethernet to the Pi doesn't help in this situation, as you'd still need to use the wifi on the ZyXel if you want halfway decent performance.
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have:
Sorry, haven’t had the chance to do that log collecting yet, however it works if I use the 2.4GHz radio on the zyxel to both use it as a client and as an available network! It seems to be an issue only on the 5GHz radio. I’ll post the configs asap!