Activating tunnels using control packets

Packet switch operating methods and packet switches detect, at a packet switch, a change in a first tunnel's ability to relay packets between the packet switch and another packet switch and, in response, send a control packet to the other packet switch. The control packet indicates a particular one of the tunnels is active on the packet switch. The packet switches are coupled together by the first tunnel and a second tunnel. A packet switch network includes a first packet switch and a second packet switch both configured to recognize disagreement regarding which one of a first tunnel and a second tunnel is active and which one is inactive in response to receiving control packets from each other and resolve the disagreement so that a particular one of the first tunnel and the second tunnel is active according to both the first packet switch and the second packet switch.