Although the big builds of dd-wrt contain IPv6 support, it doesn’t support ip6tables. Hence, I choose to use the mini build (which gives me the most free space) and add the missing parts myself. I shamelessly used OpenWRT modules to save me the trouble of figuring out how to compile each library. (Unfortunately, my router isn’t supported by OpenWRT, so I need to stay with dd-wrt for the base system).