This is brief post about a solution I came up with a while back. Problem: I needed three wireless networks to cover my home, home office and granny flat. I was able to run Cat5 cables to the two locations.
After some research, I decided to give DD-WRT a try as a replacement for the notoriously flaky manufacturer firmware for commodity hardware. I have always found that the factory firmware offers an interface that is inconsistent, buggy, hard to use, and often doesn't use standard naming conventions for features, so it's remarkably hard to work out what settings to use.
However none of my existing random modems supported DD-WRT, so I decided to buy something that was on the supported list.
The Linksys E1200, supporting wireless N, is around $55 AU ($35 US) and is still available now (https://www.ebay.com.au/p/177908116) , even though it's becoming scarce. Wireless N is still plenty fast enough for me.
The steps are pretty simple, just go here: https://wiki.dd-wrt.com/wiki/index.php/Linksys_E1200v2
and follow instructions.
It was easy to use my Internet Provider's modem as the main DHCP server, and just switch off DHCP and all other services on the E1200s and use them simply to create new wifi networks to extend the range of the VDSL service.
DD-WRT proved to be very reliable, consistent, and easy to use. These have served me for about 6 years now without any issues whatsoever.
At work, I note I use a cheap ($300) Netgate box running pfSense for the main router for the entire organisation, including three subnets and routing over a fixed fibre line to a secondary premises. I cannot say enough good things about pfSense, it is far better than DD-WRT but with an associated rise in hardware costs, although it is free and you can run it on a variety of hardware.
For me, DD-WRT was still the best budget home solution.
