To perform multi server migrations you need multiple servers configured within a virtual network. This guide shows you how to create a virtual network and VM in Google Compute Engine.
Go to https://console.developers.google.com/ and select a project or create a new one
Go to Networking and select Create Network
Supply a name and either configure a subnetwork or select Automatic which creates a subnet in each region and provides an IP range. Select all Firewall Rules and Create
Go to Compute Engine and Create Instance
Give your instance a name, select a zone, machine type and boot disk (Windows Server 2008 or 2012)
Expand ‘Management, disk, networking, access & security options’ and select Networking. Select your previously created network and subnetwork then Create