ccna题库问题

qwer12tyu34

QUESTION 70
Refer to the exhibit.A router received these five routes form different routing information sources.which two routes dose the router install in the routing table?
(choose two)
A. iBGP route 10.0.0.0/30
B. RIP route 10.0.0.0/30
C. EIGRP route 10.0.0.1/32
D. OSPF route 10.0.0.0/30
E. OSPF route 10.0.0.0/16
QUESTION 144
Refer to the exhibit,if the network environment is operating normally,which type of device must be connected to interface fastethernet0/1?
ip arp inspection vlan 2-10
interface fastethernet 0/1
ip arp inspection trust
A. DHCP client
B. PC
C. router
D. access point
QUESTION 148
The SW1 interface g0/1 is in the down/down state.which two configurations are valid reasons for the interface conditions?(choose two)
A. There is a duplex mismatch
B. There is a speed mismatch
C. There is a protocol mismatch
D. The interface is shut down
E. The interface is error-disabled
QUESTION 225
When implementing a router as a DHCP server, which two features must be configured? (Choose two)
A. relay agent information
B. address pool
C. smart-relay
D. database agent
E. manual bindings

QUESTION 234
What is a recommended approach to avoid co-channel congestion while installing access points that use the 2.4 GHz frequency?
A. different nonoverlapping channels
B. different overlapping channels
C. one overlapping channel
D. one nonoverlapping channel

QUESTION 262
Which device tracks the state of active connections in order to make a decision to forward a packet through?
A. wireless access point
B. firewall
C. wireless LAN controller
D. router

这几道题目答案要怎么选，题库答案都不一致，大佬帮忙解答下吧，不然考试肯定要挂

leort

第70道题是指收到那5条路由会把其中哪两条加表
光說路由表肯定是最长掩码匹配原则,如果掩码位数一致
那就比较AD值, 相同AD值那就比较 度量值 举例如:EIGRP的METRIC / OSPF的COST
所以/32位一定加表 然后是/30位的3条作出比较
OSPF AD值110; RIP AD值120;  IBGP为200
OSPF最少所以胜出
答案是C和D

第144题考的是DAI 这玩意好像是用来防止终端被ARP攻击的
其实我也不太熟悉,但相信不会设成PC
因为DAI这功能就是用作保护PC的,TRUST代表不在该接口启用 = 没有保护
项目中曾经设定过这条命令在上行口 配合dhcp snooping来做的
所以我估计答案是ROUTER , 因为DHCP CLIENT和PC感觉上本质相同,应该两个答案都是错的
那就只剩AP了,AP感觉上也不是正确答案

第148条
估计是D和E
ERROR DISABLE是肯定双DOWN的 交换机的接口预设UP 但人为SHUTDOWN也是双DOWN

第225条
地址池是肯定要配的 所以B一定正确
另外一个是manuel binding
A指的是ip helper-address肯定是错的
smart-relay也是中继类型的东西,估计也是错的
那就只剩三个了,ADDRESS POOL是肯定必需的
至于manuel binding和DHCP AGENT
我会选前者,因为后者有点尴尬
这玩意我在外国的技术博客搜的时候看到思科设备的DHCP 数据库默认是绑定内存的,也就是说重启设备所有DHCP数据就会消失 但可以手动选择FTP存储
但回到题目上它是说必需配置的信息
那就意味着默认自带=不必配置
而且它在这条题目上写的是AGENT = 代理,估计是指手动配置的那种.
所以是ADDRESS POOL和manuel binding



第234条
问的是无线如何避免信道拥塞
就我以前做过的WIFI项目上看的文档 2.4G一般都是用1 6 11 这样去分隔开 因为它们彼此之间的信道是不重叠的
我在外国的无线技术博客看到,对于2.4G信道的描述如下

In the 2.4 GHz band, 1, 6, and 11 are the only non-overlapping channels. Selecting one or more of these channels is an important part of setting up your network correctly.

代表这种做法可以降低干扰
这题目不好说,等大神回答,我个人选A
首先B和C一定是错的,信道重叠代表肯定容易互相干扰做成拥塞
所以只剩A和D


第262条相信是B了
因为貌似只有状态防火牆才会追踪连接的活动状态去判断是否进行包转發
根据wikipedia对于状态防火牆的定义如下

In computing, a stateful firewall is a network-based firewall that individually tracks sessions of network connections traversing it. Stateful packet inspection, also referred to as dynamic packet filtering, is a security feature often used in non-commercial and business networks.

因此可以认为答案是B 防火牆

以上都是我个人看法,如有错误请大神指正

qwer12tyu34

leort 发表于 2021-5-7 21:32
第70道题是指收到那5条路由会把其中哪两条加表
光說路由表肯定是最长掩码匹配原则,如果掩码位数一致
那就 ...

大佬解释的很详细，就144不是很认同，144的有vlan更像是隔离广播域的，ap既像末端设备，又类似于交换机，感觉也像

两只老虎爱吃鱼

鸿鹄之志~~~~

clw@2020

which two features must be configured? (Choose two) A. relay agent i

boat123

学到了

sinomux

受教了

dolly

谢谢分享、

TCP我是UDP

123