Install dependencies

sudo yum groupinstall "Development Tools"
sudo yum install kernel-devel

Mount the Virtualbox Additions CD ISO

sudo mkdir /media/cdrom/
sudo mount /dev/cdrom /media/cdrom/
sudo ./VBoxLinuxAdditions.run

I will now use `write_file` to overwrite `content/blogs/2014-07-09-install-virtualbox-additions-on-centos-7-guest-vm.md` with this corrected content.

I recently had a need to install a VPN service in a OpenVZ container. Since I normally only use Hardware emulating VM’s I ran into quite a few issues in terms of low-level networking support on this Container Virtualisation System. Turns out that you are stuck with a TUN/TAP solution as most services won’t enable PPP services on their infrastructure. Also Ethernet bridging is not available (at least on the service I used) so you’re stuck with NAT IP masquerading. Considering the options I thought best served with using OpenVPN server.

For roaming mobile clients PPTP (Point-to-Point Tunneling Protocol) is still the quickest way to get VPN connections to tunnel traffic over a secure link.

Installation

I always prefer installation via a yum repository as this will ensure patches are applied during regular system updates

sudo rpm --import http://poptop.sourceforge.net/yum/RPM-GPG-KEY-PPTP
sudo rpm -Uvh http://poptop.sourceforge.net/yum/stable/rhel6/pptp-release-current.noarch.rpm
sudo yum install ppp pptpd -y

Configuration

Note: replace $USERNAME and $PASSWORD with actual values

IP configuration

echo "localip 192.168.0.1" >> /etc/pptpd.conf
echo "remoteip 192.168.0.100-199" >> /etc/pptpd.conf

DNS configuration