MVPN is built upon a new IPtunneling technology that USES multicast group addresses as tunnel destination addresses.
MVPN是以新的IP隧道技术为基础构建起来的，该技术将组播组地址用作隧道目的地址。
2
The implementation of IP-over-IPtunneling (IPIP) and the Generalized Routing Encapsulation (GRE) protocol is based on the creation of a virtual device.
IPIP的实现和通用路由封装协议是基于一个虚拟设备的创建。
3
The ESP header is located after the IP header and before the transport mode protocol (UDP or TCP) or before an encapsulated IP header when using tunneling.