CCNA题库答案变动问题

wuxiaodo@126.co

最近19.1.8的题库，有些题目变了，感觉解释不通啊. 不知道谁能分析下。

1. 378题以前的解释是选A. It is always performed automatically，不知道为什么要改成B
最近考试的有没有考到这几个题目?

QUESTION 378
Which statement about spanning-tree root-bridge election is true?
A. It is always performed automatically
B. Each VLAN must have its own root bridge
C. Each VLAN must use the same root bridge
D. Each root bridge must reside on the same root switch
Correct Answer: B



2.QUESTION 396 ，以前选D，现在选B，不知道理由是什么
which statement about upgrading a cisco IOS device with TFTP server ?
A. the operation is performed in active mode
B. the operation is performed in unencrypted format
C. the operation is performed in passive mode
D. the cisco IOS device must be on the same LAN as the TFTP server
Correct Answer: B




3.还有512题，以前是AD,现在是AE，不知道怎么解释。
QUESTION 512
Which two statements about static routing are true? (Choose two.)
A. Its default administrative distance is lower than EIGRP.
B. Its provides only limited security unless the administrator performs additional configuration
C. Its allows packets to transit a different path if the topology changes.
D. Its initial implementation is more complex than OSPF
E. Its allows the administrator to determine the entire path of a packet

Correct Answer: AE

4.QUESTION 58
What is the status of port-channel if LACP is misconfigured?
A. Forwarding
B. Enabled
C. Disabled
D. errdisabled
Correct Answer: C

5.QUESTION 42
Which two statements about IPv4 multicast traffic are true? (Choose two.)
A. It burdens the source host without affecting remote hosts.
B. It uses a minimum amount of network bandwidth.
C. It is bandwidth-intensive.
D. It simultaneously delivers multiple streams of data.
E. It is the most efficient way to deliver data to multiple receivers.
Correct Answer: BE

david99022

如果你只是要考張NA，沒有要搞懂，那就題庫背一背吧。題庫一定有錯誤的答案，畢竟官方沒給標準答案。
如果是想要釐清觀念，那就說說你自己的想法吧。

QUESTION 378
Which statement about spanning-tree root-bridge election is true?
A. It is always performed automatically
B. Each VLAN must have its own root bridge
C. Each VLAN must use the same root bridge
D. Each root bridge must reside on the same root switch
這題我會選B，A的選舉跟是否收到BPDU有關，雖然看起來是自動的沒錯，但如果沒有BPDU封包，設備就部會進行選舉。

QUESTION 396 ，以前选D，现在选B，不知道理由是什么
which statement about upgrading a cisco IOS device with TFTP server ?
A. the operation is performed in active mode
B. the operation is performed in unencrypted format
C. the operation is performed in passive mode
D. the cisco IOS device must be on the same LAN as the TFTP server
這題我選B，D選項看起來蠻正確的,但他用了must be的字眼，在不同lan中也可以透過路由來完成TFTP。TFTP是簡易式的通訊協定，連帳號密碼都沒有了，一定是未加密的通訊。

Q512题，以前是AD,现在是AE，不知道怎么解释。
QUESTION 512
Which two statements about static routing are true? (Choose two.)
A. Its default administrative distance is lower than EIGRP.
B. Its provides only limited security unless the administrator performs additional configuration
C. Its allows packets to transit a different path if the topology changes.
D. Its initial implementation is more complex than OSPF
E. Its allows the administrator to determine the entire path of a packet
選項AE敘述非常正確，反而是D一看就是錯的，一個是靜態路由，一個是動態路由，複雜程度差很多。

QUESTION 58
What is the status of port-channel if LACP is misconfigured?
A. Forwarding
B. Enabled
C. Disabled
D. errdisabled
這就是D，沒什麼好說的，port-channel兩邊設定不一樣，不會進到errdisabeld，頂多就port-channelr建不起來

QUESTION 42
Which two statements about IPv4 multicast traffic are true? (Choose two.)
A. It burdens the source host without affecting remote hosts.
B. It uses a minimum amount of network bandwidth.
C. It is bandwidth-intensive.
D. It simultaneously delivers multiple streams of data.
E. It is the most efficient way to deliver data to multiple receivers.
這題我也不確定，但AC選項一看就是錯的。E選項我會選，畢竟這就是multicast的概念，BD選項應該蠻多人想法都不一樣的，就看考試當下了。畢竟這兩個選項也不是很重要

小乔

没有原因 不会乱改的

syq1239

sunzhee

二楼解答

somebro

tommvli

xinsibuhui

看看

勁爆

感謝大大的分享~~~

zhao_zhen

11111111111

jackmu9018

小依

这些考试都是只要背题库就能通过了麽？

kristisipe

Nice!