Automated topology-discovery processes, wherein topology-related information is exchanged among the nodes of a network using data-plane headers of transmitted packets, and without relying on conventional control-plane topology-discovery protocols. For such “control-plane-less” topology discovery, a discovery-enabling Topology Discovery Header (TDH) may be encoded as an extension of the data-plane header. Such TDH can be used, e.g., to carry various types of pertinent information typically relied-upon by the relevant network entities for topology-discovery purposes. In some embodiments, topology discovery is fully migrated from the control plane to the data plane and is substantially integrated into the corresponding Packet Switching Technology. Due to this migration, some features of some conventional control protocols may not be critically needed in the corresponding communication networks. As a result, adaptation, streamlining, replacement, and/or elimination of some of such control protocols may beneficially be implemented, e.g., to meet the needs of the network operator in a cost-effective manner.