Explanation: If you create a VPN connection, you must specify the type of routing that you plan to use, which will depend upon on the make and model of your VPN devices. If your VPN device supports Border Gateway Protocol (BGP), you need to specify dynamic routing when you configure your VPN connection. If your device does not support BGP, you should specify static routing.
Reference:
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_VPN.html