OpenWRT

OpenWRT is an aftermarket firmware for consumer routers. It's open source and very powerful.

The OpenWrt Project is a Linux operating system targeting embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. For developers, OpenWrt is the framework to build an application without having to build a complete firmware around it; for users this means the ability for full customization, to use the device in ways never envisioned.

If you have the opportunity to purchase some new or refurbished hardware, you absolutely need to consult the supported devices table and do your choices.

I suggest you choose a device with more than one ethernet port (WAN or LAN doesnt matter), since you never know when plugging in a cable might be useful, and one port will always be required for the connection to the wired backbone.

I have selected a Netgear R6220 which is a nice 2.4Ghz/5Ghz WiFi router/Access Point with 4 LAN and 1 WAN gigabit ethernet ports. It's very versatile and quite capable. It comes in different models. with or without USB port. It's not available to buy new anymore, but i managed to buy five of them and they have been going rock solid for many years.