One embodiment of the present invention provides a switch system. The switch includes a port that couples to a server hosting a number of virtual machines. The switch also includes a link tracking module. During operation, the link tracking module determines that reachability to at least one end host coupled to a virtual cluster switch of which the switch is a member is disrupted. The link tracking module then determines that at least one virtual machine coupled to the port is affected by the disrupted reachability, and communicates to the server hosting the affected virtual machine about the disrupted reachability.