Service insertion in basic virtual network environment

A processing system includes: a first service machine having a first service module; and a first service switch; wherein the first service machine and the first service switch are configured for logically coupling between virtual machines and a virtual switch; wherein the first service machine comprises a first communication interface and a second communication interface, the second communication interface configured for communication with the first service switch. A processing system includes: a service module; a first communication interface for communication with a virtual switch, the virtual switch configured for communicating with virtual machines; a second communication interface for communication with the virtual switch; the first communication interface being associated with a plurality of VM-based network segments at the virtual switch, the plurality of VM-based network segments corresponding with the plurality of virtual machines, respectively; and wherein the second communication interface is associated with original network segments at the virtual switch.