1、1 Convert the binary number 10111010 into its hexadecimal equivalent. Select the correct answer from the list below. 85 90 BA A1 B3 1C 2 Which of the following describe interframe spacing? (Choose two.) the minimum interval, measured in bit-times, that any station must wait before sending another fr
2、ame the maximum interval, measured in bit-times, that any station must wait before sending another frame the 96-bit payload padding inserted into a frame to achieve a legal frame size the 96-bit frame padding transmitted between frames to achieve proper synchronization the time allowed for slow stat
3、ions to process a frame and prepare for the next frame the maximum interval within which a station must send another frame to avoid being considered unreachable 3 When a collision occurs in a network using CSMA/CD, how do hosts with data to transmit respond after the backoff period has expired? The
4、hosts return to a listen-before-transmit mode. The hosts creating the collision have priority to send data. The hosts creating the collision retransmit the last 16 frames. The hosts extend their delay period to allow for rapid transmission. 4 After an Ethernet collision, when the backoff algorithm i
5、s invoked, which device has priority to transmit data? the device involved in the collision with the lowest MAC address the device involved in the collision with the lowest IP address any device in the collision domain whose backoff timer expires first those that began transmitting at the same time
6、5 Which of the following is a drawback of the CSMA/CD access method? Collisions can decrease network performance. It is more complex than non-deterministic protocols. Deterministic media access protocols slow network performance. CSMA/CD LAN technologies are only available at slower speeds than othe
7、r LAN technologies. 6Refer to the exhibit. The switch and workstation are administratively configured for full-duplex operation. Which statement accurately reflects the operation of this link? No collisions will occur on this link. Only one of the devices can transmit at a time. The switch will have
8、 priority for transmitting data. The devices will default back to half duplex if excessive collisions occur. 7 Why do hosts on an Ethernet segment that experience a collision use a random delay before attempting to transmit a frame? A random delay is used to ensure a collision-free link. A random de
9、lay value for each device is assigned by the manufacturer. A standard delay value could not be agreed upon among networking device vendors. A random delay helps prevent the stations from experiencing another collision during the transmission. 8In the graphic, Host A has reached 50% completion in sen
10、ding a 1 KB Ethernet frame to Host D when Host B wishes to transmit its own frame to Host C. What must Host B do? Host B can transmit immediately since it is connected on its own cable segment. Host B must wait to receive a CSMA transmission from the hub, to signal its turn. Host B must send a reque
11、st signal to Host A by transmitting an interframe gap. Host B must wait until it is certain that Host A has completed sending its frame. 9 Ethernet operates at which layers of the OSI model? (Choose two.) Network layer Transport layer Physical layer Application layer Session layer Data-link layer 10
12、 What does the IEEE 802.2 standard represent in Ethernet technologies? MAC sublayer Physical layer Logical Link Control sublayer Network layer 11 Which statements correctly describe MAC addresses? (Choose three.) dynamically assigned copied into RAM during system startup layer 3 address contains a 3
13、 byte OUI 6 bytes long 32 bits long 12Refer to the exhibit. Host_A is attempting to contact Server_B. Which statements correctly describe the addressing Host_A will generate in the process? (Choose two.) A packet with the destination IP of Router_B. A frame with the destination MAC address of Switch
14、_A. A packet with the destination IP of Router_A. A frame with the destination MAC address of Router_A. A packet with the destination IP of Server_B. A frame with the destination MAC address of Server_B. 13 Host A has an IP address of 172.16.225.93, a mask of 255.255.248.0, and a default gateway of
15、172.16.224.1. Host A needs to send a packet to a new host whose IP is 172.16.231.78. Host A performs the ANDing operation on its address and subnet mask. What two things will occur? (Choose two.) Host A will get a result of 172.16.224.0 from the AND process. Host A will send on to the media a broadc
16、ast frame that contains the packet. Host A will broadcast an ARP request for the MAC of the host 172.16.231.78. Host A will change the destination IP of the packet to 172.16.224.1 and forward the packet. Host A will encapsulate the packet in a frame with a destination MAC that is the MAC address ass
17、ociated with 172.16.224.1. 14 Which two features make switches preferable to hubs in Ethernet-based networks? (Choose two.) reduction in cross-talk minimizing of collisions support for UTP cabling division into broadcast domains increase in the throughput of communications 15 Ethernet operates at wh
18、ich layer of the TCP/IP network model? application physical transport internet data link network access 16 What are three functions of the upper data link sublayer in the OSI model? (Choose three.) recognizes streams of bits identifies the network layer protocol makes the connection with the upper l
19、ayers identifies the source and destination applications insulates network layer protocols from changes in physical equipment determines the source of a transmission when multiple devices are transmitting 17 What three primary functions does data link layer encapsulation provide? (Choose three.) add
20、ressing error detection frame delimiting port identification path determination IP address resolution 18 What are the two most commonly used media types in Ethernet networks today? (Choose two.) coaxial thicknet copper UTP coaxial thinnet optical fiber shielded twisted pair 19Refer to the exhibit. W
21、hich option correctly identifies content that the frame data field may contain? preamble and stop frame network layer packet physical addressing FCS and SoF 20 What is the primary purpose of ARP? translate URLs to IP addresses resolve IPv4 addresses to MAC addresses provide dynamic IP configuration to network devices convert internal private addresses to external public addresses
