Some embodiments provide a method for a first network controller located at a first physical domain that manages a logical network spanning several physical domains including the first domain. The method detects that connectivity is lost between the first network controller and a second network controller located in a second one of the physical domains. The method identifies a set of forwarding elements managed by the first network controller that implement the logical network. The method instructs the set of forwarding elements to drop packets for the logical network received from forwarding elements in the second physical domain.