Abstract: A method, computer environment and cloud server configured to facilitate communication among plural networks established in the cloud server. The cloud server (400) includes hardware components (802) configured to process and store information; a hypervisor (430) configured to run on the hardware components (802) and also configured to provide a virtual platform in a kernel space (404); a first virtual machine (410) running on the virtual platform in a user space (402); a first L2aaS network (414) connected to the first virtual machine (410), the first L2aaS network (414) being located in the kernel space (404); a second virtual machine (416) running on the virtual platform in the user space (402); a second L2aaS network (418) connected to the second virtual machine (416), the second L2aaS network (418) being located in the kernel space (404); and a virtual router (424) located in the kernel space (404) and connected to the first L2aaS network (414) and the second L2aaS network (418).