The good news here is that a Draytek, out-the-box, is already setup for L2TP/IPsec. Just add a pre-shared key, your usernames/passwords, and you are good to go. The other good news is that Windows also supports L2TP/IPsec out-of-box. Just add
VPNs – the easy way
This series of posts describe how VPNs using various routers can be implemented quickly and easily. It covers both dial-up and site-to-site (S2S) VPNs, and includes walk-throughs, configuration notes and troubleshooting steps. It describes the simplest way of deploying and