There’s a fairly quick and simple method to configure VPN from the Draytek to iPhone.
I’m configuring this on a Draytek 2860n-Plus but the same process applies to most Draytek interfaces.
If you don’t have a static IP then you can configure using a free DynDNS name from no-ip.org (Other dynamic DNS providers are also available)
This method is using L2TP with IPSEC. A guide to the various VPN types can be found on HowtoGeek
Draytek 2860 Setup
“VPN and Remote Access -> VPN and Remote Access -> Remote Access Control”
Enable “IPsec” & “L2TP” VPN Services (These may already be enabled by default)
“VPN and Remote Access -> IPsec General Setup”
Configure Pre-Shared Key (Will be used later on)
“VPN and Remote Access -> Remote Dial-in User”
Enable L2TP with IPsec VPN user account & set a user password (Pre-Shared Key is configured in separate process above)
“Settings -> General -> VPN”
Configure server name, this can be a direct IP or DNS (using no-ip.org or other service), enter user password and secret (Pre-Shared Key), “Send All Traffic” will ensure all data pumps down the VPN and won’t use Split Tunnel