思科认证考试
Which of the protocols below, operates at Layer 2 of the OSI model, and is used to maintain a loop-free network?（）A、RIPB、STPC、IGRPD、CDPE、VTP
题目
Which of the protocols below, operates at Layer 2 of the OSI model, and is used to maintain a loop-free network?（）
- A、RIP
- B、STP
- C、IGRP
- D、CDP
- E、VTP
参考答案和解析
相似问题和答案
第1题：
A. set protocols rsvp cspf-enable
B. set protocols mpls cspf-enable
C. set protocols rsvp traffic-engineering
D. set protocols ospf traffic-engineering
第2题：
After logging into the RtrB router, you issue the "show interface" command as displayed below:After considering the effects of the command output illustrated in the exhibit above,which of the following protocols are operational on the serial link?（）
A. PPP
B. IP
C. Compression
D. IPX
E. Multilink
F. ATX
第3题：
Which three of the protocols below belong to the application layer? (Select three answer choices)
A. ARP
B. HTTPS
C. SMTP
D. CDP
E. TFTP
F. ICMP
B,C,E 解析：Explanation:
The application layer is the highest OSI layer, and protocols at this layer are end-user oriented. HTTPS so people can get information on the internet, SMTP so people can manage networks, and TFTP so people can download files.
Incorrect Answers:
A, D, F. ARP, CDP, ICMP are protocols that equipment like routers and switches use to communicate with themselves, and belong to lower levels on the model.
第4题：
Which two routing protocols require a metric to be configured when redistributing routes from other protocols?（）
- A、RIP
- B、BGP
- C、IS - IS
- D、OSPF
- E、EIGRP
正确答案:A,E
第5题：
Which of the routing protocols shown below support both VLSM and route summarization?（）
- A、IGRP
- B、EIGRP
- C、RIP v1
- D、RIP v2
- E、OSPF
- F、VTP
- G、CDP
正确答案:B,D,E
第6题：
A. HDLC
B. NCP
C. PAP
D. LAPD
E. LAPB
F. None of the above
第7题：
Which one of the protocols below allows a router to respond to an ARP request destined to a remote host?（）
- A、Gateway DP
- B、Reverse ARP
- C、proxy ARP
- D、Inverse ARP
- E、indirect ARP
正确答案:C
第8题：
Which of the protocols below, operates at Layer 2 of the OSI model, and is used to maintain a loop-free network?
A. RIP
B. STP
C. IGRP
D. CDP
E. VTP
F. None of the above
B 解析：Explanation:
STP (spanning tree protocol) operates on layer 2 to prevent loops in switches and bridges.
Incorrect Answers:
A, C. RIP and IGRP are routing protocols, which are used at layer 3 to maintain a loop free routed environment.
D. CDP does indeed operate at layer 2, but it doest not provide for a loop free topology. CDP is used by Cisco devices to discover information about their neighbors.
E. VTP is the VLAN Trunking Protocol, used to pass VLAN information through switches. It relies on the STP mechanism to provide a loop free network.
第9题：
Which one of the WAN data-link protocols below is used for out-of-band signaling?（）
- A、HDLC
- B、NCP
- C、PAP
- D、LAPD
- E、LAPB
- F、None of the above
正确答案:D
第10题：
Which three of the protocols below belong to the application layer?（）
- A、ARP
- B、HTTPS
- C、SMTP
- D、CDP
- E、TFTP
- F、ICMP
正确答案:B,C,E