1. A method for operating a network that utilizes provider backbone bridging (PBB) to create a PBB domain, wherein the network includes a first customer edge (CE) device connected to first and second PBB provider edge (PE) devices and a second CE device connected to a third PBB PE device, the method comprising: at the third PBB PE device, learning customer media access control (CMAC)-to-backbone MAC (BMAC) associations that map a CMAC from a customer domain to a BMAC of the first PBB PE device; detecting a service failure that requires a path change for customer traffic to reach the first CE device from the second CE device; and triggering a flush of the CMAC-to-BMAC associations at the third PBB PE device in response to the detected service failure.