虚拟机迁移系统网络连接重定向技术*

针对虚拟机（virtual machine,VM）在不同子网间进行在线迁移时，因网络接入点发生改变而无法继续通信的问题，设计和实现了基于代理移动IP（proxy mobile IP,PMIP）的网络连接重定向系统。当VM迁移到外部子网时，将其看做移动节点，不改变IP地址，通过外部网络和家乡网络之间的双向隧道传输所有来自和发往该VM的网络数据。此方案中跨子网的在线迁移行为对VM以及与VM通信的节点透明。实验证明了该系统可以保证VM较快的网络切换速度和较好的网络通信性能。

Network connection redirection technology in virtual machine migration system

To solve the problem that virtual machine (VM) could not communicate with nodes in network after it was migrated lively from a subnet to another subnet because its network access point was changed,designed and implemented a solution of network redirection based on proxy mobile IP (PMIP).When migrated an VM to an outer subnet, it was seen as a mobile node and its IP address configuration was not changed. The redirection system created a bi-directional tunnel between the foreign agent in foreign network and the home agent in home network, through which all traffic to and from the VM travels. This solution realized live migration across subnets which was transparent to VM and its correspondent node. The experimental results show the system can provide quick network switch and high network performance to the VM.