当前位置: 首页 > 问题分类 > 计算机类考试 > 思科认证 > 问题详情
问题

Which three statements are true about the operation of a full-duplex Ethernet network, which is being used in the Ezonexam LAN? (Choose three)

A.Ethernet hub ports are preconfigured for full-duplex mode.

B.The host network card and the switch port must be capable of operating in full-duplex mode.

C.There are no collisions in full-duplex mode.

D.In a full-duplex environment, the host network card must check for the availability of the network media before transmitting.

E.A dedicated switch port is required for each full-duplex node.

参考答案
正确答案:BCE
解析:Explanation:
Half-duplex Ethernet is defined in the original 802.3 Ethernet and Cisco says you only use one wire pair with a digital signal running in both directions on the wire. It also uses the CSMA/CD protocol to help prevent collisions and to permit retransmitting if a collision does occur. If a hub is attached to a switch, it must operate in half-duplex mode because the end stations must be able to detect collisions.

Half-duplex Ethernet-typically 10BaseT-is only about 30 to 40 percent efficient as Cisco sees it, because a large 10BaseT network will usually only give you 3- to 4Mbps-at most. Full-duplex Ethernet uses two pairs of wires, instead of one wire pair like half duplex. Also, full duplex uses a point-to-point connection between the transmitter of the transmitting device and the receiver of the receiving device, which means that with full-duplex data transfer, you get a faster data transfer compared to half duplex.

And because the transmitted data is sent on a different set of wires than the received data, no collisions occur. The reason you don't need to worry about collisions is because now Full-duplex Ethernet is like a freeway with multiple lanes instead of the single-lane road provided by half duplex. Full-duplex Ethernet is supposed to offer 100 percent efficiency in both directions; this means you can get 20Mbps with a 10Mbps Ethernet running full duplex, or 200Mbps for FastEthernet.
您可能感兴趣的试题
  • How can a Ezonexam administrator determine if a router has been configured when it is first powered up?

    A.A configured router prompts for a password

    B.A configured router goes to the privileged mode prompt

    C.An un configured router goes into the setup dialog

    D.An un configured router goes to the enable mode prompt

  • FTP工作在OSI哪一层()

    A.会话层

    B.表示层

    C.传输层

    D.应用层

  • An administrator issues the show ip interface s0/0 command and the output displays that interface Serial0/0 is up, line protocol is up.

    What does 'line protocol is up' specifically indicate about the interface?

    A.The cable is attached properly.

    B.CDP has discovered the connected device.

    C.Keepalives are being received on the interface.

    D.A carrier detect signal has been received from the connected device.

    E.IP is correctly configured on the interface.

  • 交换机工作在OSI七层模型的哪一层()

    A.物理层

    B.数据链路层

    C.网络层

    D.传输层

×
验证