View all MAC addresses in the CAM table: Switch#show mac address-table In case the switch receives a frame from a source MAC address already in the CAM, only its timestamp is updated. If the MAC address is detected on a different port, the switch creates a new record with the new port, vlan and a new timestamp then the previous entry is deleted. If, after 300 seconds, no other frame is detected on that port, the MAC is removed from the CAM table. The CAM table stores a MAC entry by default is 300 seconds.
Switches can hold many MAC addresses in their CAM table, but they are limited. Finally, the switch sends the frames to the destination based on the information learned.īroadcast and multicast MAC addresses also generate flooding: The computers in the same vlan receive the Unknown Unicast, and the computer with the destination MAC address replies to the switch for the switch registers its MAC and vlan with the destination port. If the destination MAC is not found in the MAC Address Table, it sends Unknown Unicast flooding to all ports belonging to the same vlan. When the frames arrive at the switch, the source MAC addresses are learned, placed in the CAM table with the port and VLAN through which they arrived, and are also added along with a timestamp, by default 300 seconds. The size of the broadcast domains can be limited through vlan segmentation, and communication between vlans is possible through a layer3 device such as a router or a multilayer switch. It sends frames based on destination MAC addresses (Media Access Control) found within the same frame based on its CAM table (Content Addressable Table).Įach switch port is a collision domain, the bandwidth is not shared, and they work in full-duplex or half-duplex.
Switches operate at layer 2 of the OSI model (Data Link).