Hi, new owner of PI 2 + PI-DAC+. just thought I would share my experiences, including router setup.
I got sound ok from the PI-DAC+ after editing the /boot/config.txt file, (using the PI 2 image found on this forum) but had problems streaming from the USB port on the router. I have a hard disk in a usb enclosure formatted to ext3 with my flac files on. I could not get runeaudio to see the drive. After a lot of head scratching I updated the router firmware with Merlins latest version (RT-AC66U_3.0.0.4_378.51_0 at time of writing - a google search for asuswrt merlin should do it) .
This firmware has built in NFS functionality, and once this was set up, runeaudio found my drive. Working perfectly.
Hope this might help someone.
tobyl