The switch dynamically builds the address table by using the MAC source address of the frames received. When the switch receives a frame, it associates the media access control MAC address of the sending network device with the LAN port on which it was received. To switch frames between LAN ports efficiently, the switch maintains an address table. Pb_user_ / Octo/ Find mac address cisco nexus / commentsĪll Ethernet switching ports maintain media access control MAC address tables.