The main purpose and logic of many network discovery protocol mechanisms in computer Ethernet networks are based on device information obtained from AFT (Address Forwarding Tables) tables stored locally in network switches.
AFT (Address Forwarding Tables)
AFT tables store a list of MAC addresses associated with the ports of each Switch device. The advantage of stored MAC addresses for each port of switches in local networks is that network administrators can use this information in different scenarios.
AFT tables containing MAC addresses can also be created by any Switch produced by different manufacturers. However, since this information can only be used in Ethernet networks, it is not compatible with network types such as WiFi or PLC (Power Line Communication).
One of the biggest reasons for using AFT tables is to obtain the physical topology of the network. Since the management and sustainability of the network is an extremely important issue by each company, obtaining and reading these tables can be beneficial for LAN security.
The physical connection structures of devices in physical network topology are important, and one of the network management tasks relies on maintaining the physical connection of the network.
However, since it is a difficult task for a network administrator to obtain such information, the complexity of performing physical topology discovery can become an easier task with the use of AFT tables containing MAC addresses.
MIB information stored by Switches and Bridges in a network is in AFT, and MAC address information in this table can be accessed from a device on a particular node.