A Physical Topology Discovery Method Based on AFTs of Down Constraint

Network physical topology discovery is the key issue for network management and application, the physical topology discovery based on Address Forwarding Table (AFT) is a hot topic on current study. This paper defines three constraints of AFTs, and proposes a tree chopping algorithm based on AFTs satisfying down constraint, which can discover the physical topology of a subnet accurately. The proposed algorithm decreases the demand for AFT integrity dramatically, and is the loosest constraint for discovering physical topology which just relies on AFTs of down ports. The proposed algorithm can also be used in the switch domain of multiple subnets.