I just bought a new router (TP-Link TL-WR740N V 4.27) and uploaded the DD-WRT firmware which was a piece of cake. No TFTP needed.
Confirmed Working: TP-Link TL-WR740N Ver 4.27 running DD-WRT v24-sp2 (04/18/14) std build 23919
Working: Nintendo Zone + Internet Access + Streetpass Tags
What...