ccna to ccnp

ccna to ccnp.B.Switch A is down C.DNS is downD.Router A is faulty9.In Figure 9.1,Router B needs to forward a PDU from PC-B to PC-A.Which MAC address will it add to the source MAC address field of the Ethernet header? A. 0000.2222.AAAA B. 0000.2222.BBBB C. 0000.3333.AAAA D. 0000.3333.BBBB1899.6 Answers to Self-Test Questions1. do hubs are physical layer forwarders and are not concerned with the bits and bytes transmitted. a refers to data link layer PDUs; b refers to network layer PDUs; c refers to transport layer PDUso2. do The MAC address must be unique within the broadcast domain (Ethernet segment.) A, B, and C are incorrect because different broadcast domains can have the same MAC address.3. Do None of these answers are correct. Reverse Address Resolution Protocol (RARP) maps Layer 2 addresses to Layer 3 addresses. a maps Layer 3 addresses to Layer 2 addresses. b assigns addressing information to hosts. c is used to share control and error information among network devices.4. Ao In subnet 10.0.2.0/24, router B needs to forward the Ethernet frame to the DNS server, so the source MAC address field of the Ethernet header contains the MAC address of router B. If this frame was sent by Router A, B would be correct; C is the destination MAC address; and D is the source MAC address used by PC-B to send the frame to Router B.5. boSYN/ACK is the response made by the Web server, so the source and destination ports are swapped, i.e., the source port is the well-known/reserved port (80). a is incorrect because port 69 is used for TFTP; C is the destination port number used when responding to the session initiator; and D contains both the reserved and dynamic port numbers.