US Patent 8997094 Migrating virtual machines between computing devices

In one example, a system includes a first computing device configured to execute a virtual machine, wherein the virtual machine is communicatively coupled to a virtual private network (VPN) via a first attachment circuit using a first set of network parameters, stop execution of the virtual machine, and create checkpoint data for the virtual machine, and a second computing device configured to execute the virtual machine, using at least some of the checkpoint data, and to cause the virtual machine to become communicatively coupled to the VPN via a second attachment circuit using a second set of network parameters different from the first set of network parameters. The system may further include a first provider edge (PE) routing device communicatively coupled to the first computing device via the first attachment circuit, and a second PE routing device communicatively coupled to the second computing device via the second attachment circuit.