I have set up my N66U running the latest Merlin fork with Astrill VPN which comes with a handy router applet that takes care of VPN connectivity (Uses OpenVPN ). All my devices on the network (Phones/PCs) are able to use this VPN tunnel perfectly well with the exception of my Chromecast. After extensive email exchanges with Astrill I have narrowed down the problem to configuration issues that aren't able to redirect 100% of Google DNS queries to the Astrill DNS server (since the Chromecast...
Chromecast + VPN DNS Issues
Chromecast + VPN DNS Issues