Many Windows servers still use Point to Point Tunneling Protocol. It’s tried and tested, but apparently not that secure. MacOS removed it because it’s obsolete.
However, if you are a technical person having the ability to troubleshoot PPtP is a life saver. This is especially true as /var/log/syslog or /var/log/messages might have too much information or just not enough. Also filtering /var/log/syslog is tricky if you’re not that familiar with egrep.
Here is the quick way to troubleshoot a PPTP connection, by way of emulation. That means, let’s create a new connection, and then run some debugging.
How to create a new VPN connection from the command line
sudo pptpsetup --create MYVPN --server xxx.xxx.xxx.xxx --username username --password password
How to debug a PPPTP connection from the command line
sudo pppd call MYVPN debug dump logfd 2 updetach