JN0-100
单选题In Ethernet networks, duplex mismatches will lower performance. Which error statistics can be seen if a duplex mismatch is present?（）A collisions on the full-duplex side; runts on the half-duplex sideB collisions on the full-duplex side; collisions on
题目
collisions on the full-duplex side; runts on the half-duplex side
collisions on the full-duplex side; collisions on the half-duplex side
collisions on the half-duplex side; framing errors on the full-duplex side
collisions on the half-duplex side; giants on the full-duplex side
相似问题和答案
第1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.
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.
第2题：
Which of the following statements correctly describe the differences between half-duplex and full-duplex Ethernet? (Select two answer choices.)
A．Full-duplex Ethernet uses CSMA/CD to prevent collisions.
B．Half-duplex Ethernet uses a loopback circuit to detect collisions.
C．A full-duplex Ethernet card allows 20Mbps for data transmission.
D．Full-duplex Ethernet makes use of two pairs of wires for data.
E．An Ethernet hub can operate both half and full duplex simultaneously.
解析：Explanation:
Half-duplex Ethernet send and receives on the same line, so a loopback needs to be set to detect collisions. Alternatively, full-duple Ethernet doesn't have to because it uses two pairs of wire, one to send and the other to receive. Collisions are not possible on full duplex Ethernet networks.
Incorrect Answers:
A. Full duplex uses both pairs of wires, so transmissions are sent on the first pair, and data that is received come in on the other pair. This prevents collisions.
C. Full duplex allows for data to be sent and received at the same time. It will not double the amount of bandwidth at any given time. The speed of the Ethernet link will remain at 10/100.
E. Hubs are shared devices and can only support one mode, unlike switches.
第3题：
You want to upgrade the Ezonexam LAN so that all ports operate in full duplex mode. Which statement is true about full-duplex Ethernet when comparing to half-duplex Ethernet?
A．Full-duplex Ethernet consists of a shared cable segment. Half-duplex provides a point-to-point link
B．Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
C．Full-duplex Ethernet can provide higher throughput than can half-duplex Ethernet of the same bandwidth
D．Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex Ethernet uses a jam signal
E．None of the above
第4题：
You work as a network engineer at TestKing.com. TestKing users have noticed extremely slow network performance, intermittent connectivity, and connection loss. After entering the show interfaces command, you notice that the Ethernet interface is configured as 100 Mbps full-duplex and that there is evidence of late collisions. What could be the cause of this problem?（）
A. duplex mismatch
B. a routing loop
C. trunking mode mismatch
D. improperly configured root bridge
E. improperly configured static VLAN
第5题：
A.collisions on the full-duplex side; runts on the half-duplex side
B.collisions on the full-duplex side; collisions on the half-duplex side
C.collisions on the half-duplex side; framing errors on the full-duplex side
D.collisions on the half-duplex side; giants on the full-duplex side
第6题：
When you compare the differences between half-duplex and full-duplex Ethernet, which of the following characteristics are exclusive to half-duplex? (Select two answer choices)
A．Half-duplex Ethernet operates in a shared collision domain.
B．Half-duplex Ethernet operates in an exclusive broadcast domain.
C．Half-duplex Ethernet has efficient throughput.
D．Half-duplex Ethernet has lower effective throughput.
E．Half-duplex Ethernet operates in an exclusive collision domain.
解析：Explanation:
A single device could not be sending a frame. and receiving a frame. at the same time because it would mean that a collision was occurring. So, devices simply chose not to send a frame. while receiving a frame. That logic is called half-duplex logic.
Ethernet switches allow multiple frames to be sent over different ports at the same time. Additionally, if only one device is connected to a switch port, there is never a possibility that a collision could occur. So, LAN switches with only one device cabled to each port of the switch allow the use of full-duplex operation. Full duplex means that an Ethernet card can send and receive concurrently.
Incorrect Answers:
B. Full duplex effectively doubles the throughput of half-duplex operation, because data can be both sent and received at the full 10/100 speed.
C, E. In half duplex operation, the network is shared between all devices in the collision domain.
第7题：
Ezonexam users have noticed extremely slow network performance, intermittent connectivity, and connection losses. After entering the "show interfaces" command, you notice that the Ethernet interface is configured as 100 Mbps full-duplex and that there is evidence of late collisions. What could be the cause of this problem?
A. Duplex mismatch
B. A routing loop
C. Trunking mode mismatch
D. Improperly configured root bridge
E. Improperly configured static VLAN
F. None of the above
A 解析：Explanation:
A duplex mismatch may result in performance issues, intermittent connectivity, and loss of communication. When troubleshooting NIC issues, verify that the NIC and switch are using a valid configuration. Some third-party NIC cards may fall back to half-duplex operation mode, even though both the switchport and NIC configuration have been manually configured for 100 Mbps, full-duplex.
This behavior. is due to the fact that NIC autonegotiation link detection is still operating when the NIC has been manually configured. This causes duplex inconsistency between the switchport and the NIC. Symptoms include poor port performance and frame. check sequence (FCS) errors that increment on the switchport.
To troubleshoot this issue, try manually configuring the switchport to 100 Mbps, half-duplex. If this action resolves the connectivity problems, you may be running into this NIC issue. Try updating to the latest drivers for your NIC, or contact your NIC card vendor for additional support.
第8题：
The Ezonexam LAN is upgrading all devices to operate in full duplex. Which statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet?
A．Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses one wire to send and receive
B．Full-duplex Ethernet consists of a shared cable segment. Half-duplex Ethernet provides a point-to-point link
C．Full-duplex Ethernet can provide higher throughout than can half-duplex Ethernet of the same bandwidth
D．Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex ethernet uses a jam signal
E．None of the above
第9题：
A. Half-duplex Ethernet operates in a shared collision domain.
B. Full-duplex Ethernet has a lower effective throughput.
C. Half-duplex Ethernet operates in a private collision domain.
D. Full-duplex Ethernet allows two-way communication.
E. Half-duplex Ethernet operates in a private broadcast domain.
第10题：
A.没有冲突（No collisions）
B.如果一台主机正在传输数据，则另外的一台主机必须要等待
C.有着更多的冲突（More collisions）
D.在性能上比half-duplex Ethernet有很大的提高