RT-AC68U can't quite set up VPN connection.

[rotorhead8]

Hey all, somewhat of a rookie here, trying to set up a PPTP VPN to access my NAS outside my home network and I'm not sure where to start with the troubleshooting. I've followed all of the tutorials I can find from ASUS, although most are outdated compared to the firmware on my router (3.0.0.4.347_542) and have followed them to the best of my ability. I just still can't seem to get it properly set up. I already have a DDNS set up through no-ip.

Here is my setup:
Router: ASUS RT-AC68U (3.0.0.4.347_542) <-- AMAZING router BTW
ISP: AT&T Uverse, 3801HGV AIO, set up to run a modified bridge mode following this tutorial: http://soc.att.com/1cZVIeN
NAS: Buffalo LS421 NAS
DDNS through no-ip.com

These are the settings I currently have set in the VPN section of my router:
http://i.imgur.com/gQDzx5S.png?1

and

http://i.imgur.com/HvrVgis.png?1

I am also running everything on a DDNS host already as well through no-ip.com.

With those settings, I keep getting this message when trying to connect the VPN:

http://i.imgur.com/YyEaAf6.png?1

Am I missing any other areas?

Thank you in advance for all your help! I have a basic knowledge of networking and I am doing my best to soak up all the knowledge I can!

 

[rotorhead8]

To the top!

 

[sinshiva]

sounds like your modem in it's super dmz mode might lack pptp passthrough, probably cant be done unless you can get a different modem with proper bridge mode, sorry

[edit/] however, you could probably get openvpn to work