Build your own VPN(pptpd) on centos7 server. I build it on my linode server which is centos7.

###1.Update centos7 yum

$ sh install-centos7-yum-pero.sh

###2.Install pptpd and run it

$ sh install-pptpd.sh

You can see it in my blog: http://zhaodg.github.io/2015/04/26/build-vpn/.

My blog address http://zhaodg.github.io.