cisco ccna practice exams

cisco ccna practice exams.Ethernet broadcast domain: All devices connected to the same LAN switch form a broadcast domain. Network layer devices such as routers can isolate broadcast domains. Ethernet broadcast domains are sometimes referred to as subnets. Figure "19. shows an example network separated into two broadcast domains by a router.Figure 1.19-The router divides the network into two broadcast domains24 Chapter 1 Network Protocols and Network Device BasicsAfter introducing the concepts of MAC address tables, dynamic MAC address learning mechanisms, and broadcast domains, an example will be given of how a switch performs the frame forwarding function.The switch independently performs forwarding decisions based on the destination MAC address of the frame. In the network shown in Figure 1-20, the MACaddress is 0200.1111.1111 (port F0/1 of the directly connected switch) is sending a frame to host C (port F0/1 of the directly connected switch) with MAC address 0200.3333.3333.Host C (port F0/3 of the directly connected switch) is sending traffic (Ethernet frames) to host C (port F0/3 of the directly connected switch).The switch's MAC address table does not have any records for Ok D to begin with. When the first frame is received from port F0/1, the switch performs the following two operations.Query the MAC address table. Since this table is empty, the switch sends this first frame outbound from all ports except the receiving port. This behavior of the switch is commonly referred to as flooding of unknown unicast frames (Hooding) o With the help of the dynamic MAC address learning mechanism, the MAC address table is updated by adding a record to the table stating that the MAC address 0200.1111.1111 was learned through port F0/1. Figure 1.20 shows the flooding process of unknown unicast frames performed by the switch, and the update of the MAC address table