Question about simple network architecture and wi-fi

Hello to everyone,

The question is, can this setup work?
I would like to put a router with OpenWrt on the same LAN where the Internet provider's clients and modem are.
So, on the Internet provider's modem I turn off dhcp but leave wi-fi on (this saves me from putting an access point behind the OpenWrt router).
I enable dhcp on the OpenWrt router so that it acts as the default gateway for clients.
The OpenWrt router will act as WireGuard VPN server in VPN with another firewall.
Will clients who connect via wi-fi surfe the Internet correctly? Will they take an IP address? Will they be able to go to VPN to reach the remote network?

thank you

  • You never explaon how you will you setup the OpenWrt's WAN connection to the modem.
  • The modems WiFi must be on the OpenWrt's LAN to serve clients

I configure the WAN on the LAN bridge, so it basically becomes a LAN port.
With this configuration I should put a static route from the openwrt router to the Internet provider's modem. My question is whether it is necessary to put a static route or NAT also from the modem to the router because then nothing would work anymore.

  • So where's WAN?
  • Also, recall my point above.

Perhaps someone else could better describe - because the config you described above won't work.

You have to place devices on OpenWrt's LAN and put your Internet connection on WAN.

Again, WiFi clients must be on OpenWrt's LAN to work.

I know what you mean, the WAN port is connected directly to the modem, although it is not really a WAN but would be more of a LAN port. I would basically be using the Openwrt router as a switch rather than a router, so at layer 2 and not layer 3.

I guess it may not work, if so I have to respect the traditional connection and separate the WAN from the LAN.

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Also BTW, per your first post (i.e. needing a gateway), you'll need Layer 3.

Ok of course.
Could this work in your opinion?

Thank you

You need to be clearer in what you want to achieve.

Do you have to use the OpenWRT router to create a completely separate LAN to the one created by your ISP modem/router? You should be aware this may lead to a double NAT scenario which can be problematic.

Or, do you want to put everything behind the OpenWRT router to essentially replace your ISP device? This is really only feasible if you can put the ISP device into a bridge mode.

Or, do you want to use the OpenWRT router to extend the already existing 'isp' LAN? I.e. the OpenWRT router only acts as a switch/AP?

The third option, however, wi-fi should be handled by the ISP modem (if it is feasible).

Thank you

In that case it just sounds like you need to set up the OpenWRT device as a dumb AP. You can leave the ISP device doing DHCP etc.

I'd start with getting it set up as an AP, then once that's working you can start looking at adding other services (such as a VPN).


  1. The ISP modem that releases DHCP what is thedefault gateway should release?

  2. In this dumb AP configuration who provides the wi-fi signal the ISP modem or the Openwrt router?

Thank you

Itself, same as I assume it's the case now.

The OpenWRT device.

But if I leave the wi-fi on the ISP modem will it work?