思科认证考试
What does a Layer 2 switch use to decide where to forward a received frame?（）A、source MAC addressB、source IP addressC、source switch portD、destination IP addressE、destination port addressF、destination MAC address
题目
What does a Layer 2 switch use to decide where to forward a received frame?（）
- A、source MAC address
- B、source IP address
- C、source switch port
- D、destination IP address
- E、destination port address
- F、destination MAC address
相似问题和答案
第1题：
A. source MAC address
B. source IP address
C. source switch port
D. destination IP address
E. destination port address
F. destination MAC address
第2题：
A. use a Layer 2 link between distribution switches
B. use a Layer 3 link between distribution switches
C. use a redundant link to the core
D. use a Layer 3 link between distribution switches with route summarization
第3题：
Regarding DHCP (dynamic host configuration protocol), which two of the following choices below are true? (Select two answer choices)
A. The DHCP Discover message uses FF-FF-FF-FF-FF as the Layer 2 destination address.
B. The DHCP Discover message uses UDP as the transport layer protocol.
C. The DHCP Discover message uses a special Layer 2 multicast address as the destination address.
D. The DHCP Discover message uses TCP as the transport layer protocol.
E. The DHCP Discover message does not use a Layer 2 destination address.
F. The DHCP Discover message does not require a transport layer protocol.
A,B 解析：Explanation:
DHCP uses UDP as its transport protocol. DHCP messages from a client to a server are sent to the DHCP server port (UDP port 67), and DHCP messages from a server to a client are sent to the DHCP client port (UDP port 68).The client broadcasts a DHCPDISCOVER message on its local physical subnet. The DHCPDISCOVER message may include options that suggest values for the network address and lease duration. BOOTP relay agents may pass the message on to DHCP servers not on the same physical subnet.
Each server may respond with a DHCPOFFER message that includes an available network address in the "ipaddr" field (and other configuration parameters in DHCP options). Servers need not reserve the offered network address, although the protocol will work more efficiently if the server avoids allocating the offered network address to another client. The server unicasts the DHCPOFFER message to the client (using the DHCP/BOOTP relay agent if necessary) if possible, or may broadcast the message to a broadcast address (preferably 255.255.255.255) on the client's subnet.
Incorrect Answers:
C. DHCP messages are broadcast to the "all hosts" address. IP multicast addresses are not used.
D. UDP is used, not TCP.
E. Since DHCP is used so that a client can obtain an IP address, a layer two destination address must be used, as the layer 3 IP address does not yet exist on the client for the return traffic.
F. DHCP, along with nearly every other type of traffic, requires the use of a transport layer protocol.
第4题：
What layer of the TMN （telecommunications management network） model does CTM fit into？（）
- A、Network management layer
- B、Element management layer
- C、Business management layer
- D、Network element layer
正确答案:B
第5题：
What dose a Layer 2 switch use to decide where to forward a received frame?（）
- A、source MAC address
- B、source IP address
- C、source switch port
- D、destination IP address
- E、destination port address
- F、destination MAC address
正确答案:F
第6题：
A. Troubleshooting is more complicated.
B. Service and switch modules are underutilized.
C. Layer 2 adjacency is required with the servers that use this design.
D. Layer 3 adjacency is required with the servers that use this design.
E. Load balancing will always occur across both access layer uplinks.
第7题：
A.source MAC address
B.source IP address
C.source switch port
D.destination IP address
E.destination port address
F.destination MAC address
第8题：
A.Layer 1 on the interface is up but Layer 2 is down.
B.Layer 2 on the interface is up but Layer 3 has not been configured.
C.The interface is administratively up but the link status is down.
D.The interface is up but has been administratively turned off.
第9题：
Which of these recommended designs provides the highest availability?（）
- A、map the Layer 2 VLAN number to the Layer 3 subnet
- B、control route propagation to edge switches using distribute lists
- C、use a Layer 2 distribution interconnection link with HSRP or GLBP
- D、use a Layer 3 distribution interconnection link with HSRP or GLBP
- E、use equal-cost Layer 3 load balancing on all links to limit the scope of queries in EIGRP
正确答案:A
第10题：
Why will a switch never learn a broadcast address?（）
- A、Broadcasts only use network layer addressing.
- B、A broadcast frame is never forwarded by a switch.
- C、A broadcast address will never be the source address of a frame.
- D、Broadcast addresses use an incorrect format for the switching table.
- E、Broadcast frames are never sent to switches.
正确答案:C