How do I use an OpenWRT device as both an extender (for the main router) as well as a firewall + NAT box?

MigratingtoLemmy@lemmy.world to Selfhosted@lemmy.world – 22 points –

Conceptually, it's fairly easy to understand - nftables, relayd, likely some firewall application.

However, is it as simple as configuring the WAN port as the WiFi interface and leaving it at that? Note that I'm not bothered about double NAT since I won't be opening any ports, and the main router cannot be touched.

I do want my own SSIDs, my VLANs, control over the firewall etc. Basically, my own network space. If anyone has done this/has an idea of the problems I might run into, please do comment!

Appreciate the help!

11

Pretend the "main router" is a hotel wifi and use the TravelMate package.
https://github.com/openwrt/packages/blob/master/net/travelmate/files/README.md

Do you even need relayd? I think relayd is for extending the existing NAT, i.e. a wireless bridge operation. At least that's how I utilized it in a previous setup. If you want to have your own NAT, I think it's enough to just connect to the upstream wireless network as a client. Not sure if you have to designate the wireless interface as WAN or not.

How would you do this? What would be the steps you take to create a double NAT + Firewall + DHCP server with the OpenWRT router behind the main router?

Depends if you want to assign IP addresses or not. If you don't, you just want your own section of the same lan, I.e.all your devices connected to your router but let dhcp pass through then you can just set itnup as an extender

He mentioned that he wants to create Second level Nat, that will require new IP addresses and DHCP in the subnet

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

Fewer Letters More Letters
AP WiFi Access Point
IP Internet Protocol
NAT Network Address Translation

3 acronyms in this thread; the most compressed thread commented on today has 7 acronyms.

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