ccna question and answer pdf

ccna question and answer pdf.1. the DoOSI reference model contains seven layers. a, b, c, and e are all functions of the OSI reference model, and therefore none are correct answers.2. the layers of the DoOSI reference model are, in descending order, the application layer, the representation layer, the session layer, the transport layer, the network layer, the data link layer, and the physical layer (f, b, a, g, e, d, c). a lists these layers in descending order; b pairs the session and representation layers and the network and data link layers; and c pairs the session and transport layers.3. the Co data link layer provides hardware addresses. a uses port numbers for multiplexing; b defines logical addresses; d does not use anyAddress. 4. MAC addresses are 48 bits long and are expressed in hexadecimal. 5.5. the Co network layer uses logical addresses rather than physical addresses to create the hierarchy. a, b, and d are all correct and therefore not the correct answer.6. bo sequence numbers and acknowledgements are used to provide reliable transport layer connectivity. a, c, and d are all used to implement traffic control.7. multiplexing of Ao connections is achieved by using socket numbers or port numbers. b refers to the data link layer; c refers to the network layer; and d does not exist at all.(1) transponder: (a) physical layer; (2) router: (c) network layer; (3) NIC: (b) data link layer; (4) switch: (b) data link layer.9.(1) data: (a) application layer; (2) frames: (f) data link layer; (3) packets: (e) network layer; (4) bits: (g) physical layer; (5) data segments: (d) transport layer.10. eo at layer 2, PC.A sends the frame to the router, which strips the layer 2 frame information and routes the layer 3 packet. When the frame is transmitted in the second segment, the router uses its MAC address as the source address and uses PC-B's MAC address as the destination address.A is incorrect because MAC addresses are used to communicate within the same segment,and the switch and PC-A are on different segments; PC-A should use the router's MAC address as the destination address.B is incorrect because PC-A should use the C and D are incorrect because Layer 3 addresses are used to communicate between different networks (network segments); therefore, the source IP address should be the IP address of PC.