Mac address lookup table
In my personal opinion, questions in this depth can not be answered from a principial point of view because they are basically asking about implementation details. Sarah, you have some very good questions here. The frame is not sent out the same port on which the frame was received.Īlso, here is good link explaining CAM and TCAM tables:
#MAC ADDRESS LOOKUP TABLE MAC#
If the destination MAC address of the received frame is the broadcast address (), the frame is sent out all ports that are in the same VLAN as the received frame. It does not flood the frame out the same port on which the frame was received. If the destination MAC address is not in the CAM table (the address is unknown), the switch sends the frame out all other ports that are in the same VLAN as the received frame. If the associated port to send the frame out is the same port that the frame originally came in on, there is no need to send the frame back out that same port, and the frame is ignored. If the destination MAC address is found in the CAM table, the switch sends the frame out the port that is associated with that destination MAC address in the CAM table. Here are the basic rules that a switch uses to carry out the frame forwarding responsibility: The CAM table shows which port the frame must be sent out in order for that frame to reach the specified destination MAC address. In order to decide where to send a frame, the switch looks at the destination MAC address in a received frame and looks up that destination MAC address in the CAM table. This information in the CAM table is used to decide how a received frame is handled. Here is what CAM table does when it receives a frame: