Devices, methods and instructions encoded on computer readable medium for implementation of a dual-adjacency between edge devices of a network site. A first edge device comprises one or more local interfaces configured for communication, via a local network, with one or more network devices co-located in a first network site. The first edge device also comprises one or more overlay interfaces configured for communication, via a core network, with one or more network devices located in one or more other network sites connected to the core network. The first edge device comprises a processor configured to establish, via at least one of the local interfaces, a site communication channel with a second edge device co-located in the first network site. The processor is further configured to establish an overlay communication channel, via at least one of the overlay interfaces, with the second edge device.