I have an outreach center that has two links connected to one cisco 4500 catalyst switch. Both are passing VLAN traffic with different vlan interfaces. One of my problems is that if one of the links goes down I have to manually change the default path to the other interface to connect to my core environment. Is there a way to route the traffic so it knows when the path is down to go through the other gateway? iBGP? Can someone point me in the right direction of what I need to be researching?