【单选题】
What information does the key length provide in an encryption algorithm?___
A. the cipher block size
B. the hash bloc k size
C. the number of permutations
D. the packet size
查看试卷,进入试卷练习
微信扫一扫,开始刷题
答案
C
解析
暂无解析
相关试题
【单选题】
How do you verify TaCACS+ connectivity to a device?___
A. You successfully log in to the device by using the local credentials
B. You connect via console port and receive the login prompt.
C. You connect to the device using SSH and receive the login prompt.
D. You successfully log in to the device by using ACS credentials
【单选题】
Which term best describes the concept of preventing the modification of data in transit and in storage?___
A. availability
B. confidentially
C. fidelity
D. integrity
【单选题】
Which loS command is used to define the authentication key for ntp?___
A. switch(config )#ntp authentication-key 1 mds Clcs
B. switch(config )#ntp authenticate
C. switch(config)#ntp trusted-key 1
D. switch(config)#ntp source 192.168.0.1
【单选题】
What is true about the cisco lOS Resilient Configuration feature ?___
A. The feature can be disabled through a remote session
B. There is additional space required to secure the primary cisco lOS image file.
C. The feature automatically detects image or configuration version mismatch.
D. Remote storage is used for securing files
【单选题】
When is the default deny all policy an exception in zone-based firewalls?___
A. when traffic terminates on the router via the self zone
B. when traffic traverses two interfaces in different zones
C. when traffic traverses two interfaces in the same zone
D. when traffic sources from the router via the self zone
【单选题】
.If an access port is assigned as an isolated port in a PVLAN, which network ports can it communicate with?___
A. promiscuous ports in the same PLVAN
B. isolated ports in the same PVLAN
C. all ports in the same PAVLAN at ILAR
D. all ports in the adjacent PVLAN
【单选题】
Which IPSEC mode is used to encypt traffic directly between a client and a server VPN endpoint?___
A. quick mode
B. transport mode
C. aggressive mode
D. tunnel mode
【单选题】
Which command do you enter to verify that a vpn connection is established between two endpoints and that the connection is passing traffic? ___
A. Firewall#sh crypto session
B. Firewall#debug crypto isakmp
C. Firewall#tsh crypto ipsec sa
D. Firewall#sh crypto isakmp sa
【单选题】
which type of Pvlan port allows communication from all port types?___
A. isolated
B. in -line
C. community
D. promiscuous
【单选题】
Which command do you enter to configure your firewall to conceal internal addresses?___
A. no ip directed-broadcast
B. no ip logging facility
C. no proxy-arp
D. no ip inspect audit-trial
E. no ip inspect
F. route
【单选题】
Which feature defines a campus area network? ___
A. It has a limited number of segments.
B. It has limited or restricted Internet access
C. It lacks ex1ternal connectivity.
D. It has a single geographic location
【单选题】
What technology can you use to provide data confidentiality data integrity and data origin authentication on your network?___
A. IPSec
B. Certificate Authority
C. IKE
D. Data
E. ncryption Standards
【单选题】
which standard is a hybrid protocol that uses oakley and skerne ke y exchanges is an ISAKMP framework?___
A. SHA
B. IPSec
C.
D. ES
【单选题】
What is the actual los privilege level of User Exec mode?___
A. 1
B. 0
C. 5
D. 15
【单选题】
What is the effect of the asa command crypto isakmp nat-traversal?___
A. It opens port 500 only on the out side interface
B. It opens port 500 only on the inside interface
C. It opens port 4500 on all interfaces that are IPSec enabled
D. It opens port 4500 only on the out side interfac
【单选题】
Which Fire POWER preproce ssor engine is used to prevent SYN attacks?___
A. Inline normalization
B. IP Defragmentation
C. Ports can
D. etection
【单选题】
Which NAT type allows objects or groups to reference an IP address ?___
A. identity NAt
B. static NAT
C. dynamic
D. dynamic NAT
【单选题】
Which Auto NAT policies are processed first?___
A. Dynamic NAT with longest prefix
B. Dynamic NAT with shortest prefix
C. static NAT with longest prefix
D. static NAT with shortest prefix
【单选题】
Which feature allows a dynamic Pat pool to se lect the next address in the pat pool instead of the next port of an existing address?___
A. next IP
B. round robin
C. dynamic rotation
D. NAT address rotation
【单选题】
Which IPS detection method can you use to detect attacks that are based on the attackers IP address?___
A. anomally-based
B. policy-based
C. signature-based
D. reputation-based
【单选题】
Which type of encryption technology has the broadest platform support?___
A. software
B. middleware
C. file-level
D. hardware
【单选题】
Which type of address translation supports the initiation of comm unications bidirectionally ?___
A. multi-session PAT
B. dynamic NAT
C. dynamic PAT
D. static NAT
【单选题】
Which label is given to a person who uses existing computer scripts to hack into computers while lacking the expertise to write the own?___
A. script kiddy
B. white hat hacker
C. hacktivist
D. phreaker
【单选题】
What is the primary purpose of a defined rule in an IPS?___
A. to configure an event action that takes place when a signature is triggered
B. to define a set of actions that occur when a specific user logs in to the system
C. to configure an event action that is pre-defined by the system administrator
D. to detect internal attacks
【单选题】
Which option is the default valuce for the Diffie- Hell man group when configuring a site-to-site VPn on an asa device ?___
A. Group 1
B. Group 2
C. Group 5
D. Group 7
【单选题】
Which feature filters CoPP packets?___
A. access control lists
B. class maps
C. policy maps
D. route maps
【单选题】
Which command is used in global configuration mode to enable AAA?___
A. configure-model aaa
B. configure aaa-modelA
C. aaa new-model
D. aaa
E. XEC
【单选题】
Which statement about the given configuration is true?___
A. The single-connection command causes the device to establish one connection for all TACACS
B. The single-connection command causes the device to process one TacAcs request and then move to the next server
C. The timeout com mand causes the device to move to the next server after 20 seconds of TACACS inactive
【多选题】
What are two well-known security terms?___
A. phishing//网络钓鱼
B. ransomware //勒索软件
C. BPDU guard
D. LACP
E. hair-pinning
【多选题】
Which two commands must you enter to securely archive the primary bootset of a device___
A. router(config )#secure boot-config
B. router(config)#auto secure
C. router(config)#secure boot-image
D. router(config)#service passw ord-encryption
【多选题】
Which two functions can SIEM provide ?___
A. correlation between logs and events from multiple systems
B. event aggregation that allows for reduced log storage requirements
C. proactive malware analysis to block malicious traffic
D. dual-factor authentication
E. centralized firewall management
【多选题】
Which two features of Cisco Web Reputation tracking can mitigate web-based threats?___
A. buffer overflow filterin dhsuowip
B. Bayesian filters
C. web reputation filters
D. outbreak filtering
E. exploit filtering
【多选题】
What are two challenges when deploying host- level IPS? ___
A. The deployment must support multiple operating systems.
B. It is unable to provide a complete networ k picture of an attack.
C. It is unable to determine the outcome of e very attack that it detects
D. It does not provide protection for offsite computers
E. It is unable to detect fragmentation attacks
【多选题】
Which technology can be used to rate data fidelity and to provide an authenticated hash for data?___
A. file reputation
B. file analysis
C. signature updates
D. network blocking
【多选题】
Which two statements about host-based iPS solutions are true?___
A. It uses only signature-based polices
B. It can be deployed at the perimeter.
C. It can be have more restrictive policies than network-based IPS
D. it works with deployed firewall
E. It can generate alerts based on be havior at the de sto
【多选题】
When two events would cause the state table of a stateful firewall to be updated? ___
A. when a packet is evaluated against the outbound access list and is denied
B. when a con nection is created
C. when rate-limiting is applied
D. when a connection s timer has expired within the state table.
E. when an outbound packet is forwarded to the outbound interface
【多选题】
Which two characteristics apply to an intrusion Prevention System(IPS)?___
A. Cannot drop the packet on its own
B. Cabled directly inline with the flow of the network traffic
C. Runs in promiscuous mode wat
D. Does not add delay to the original traffic
E. Can drop traffic based on a set of rules
【多选题】
crypto ipsec trans form-set myset esp-md5-hmac esp-aes-256,What are two effects of the given command?___
A. It configures authentication use AES 256.
B. It configures authentication to use MD5 HMAC
C. It configures authentication use AES 256.
D. It configures encryption to ase MD5 HMAC.
E. It configures encryption to use AES 256
【多选题】
your security team has discovered a malicious program that has been harvesting the CEos email messages and the com pany 's user database for the last 6 months. What are two possible types of attacks your team discovered?___
A. social activism
B. EPolymorphic Virus
C. advanced persistent threat
D. drive-by spyware
E. targeted malware
【单选题】
以下关于数据处理的叙述中,不正确的足___。
A. :数据处理不仅能预测不久的未来,自时还能影响未
B. :数据处理和数据分析可以为决策提供真知灼见
C. :数据处理的重点应从技术角度去发现和解释数据蕴涵的意义
D. :数据处理足从现实世界到数据,冉从数据到现实世界的过程
推荐试题
【单选题】
双闭环调速系统比单闭环调速系统的起动时间___。
A. 长
B. 短
C. 不快也不慢
D. 不定
【单选题】
当晶闸管一直流电动机无静差调速系统在稳定运行时,速度反馈电压___速度给定电压。
A. 小于
B. 大于
C. 等于
D. 不定
【单选题】
当晶闸管一直流电动机转速负反馈调速系统中,当负载电流增加后晶闸管整流器输出电压将___。
A. 增加
B. 减小
C. 不变
D. 不定
【单选题】
在调试晶闸管一直流电动机转速负反馈调速系统时,若把转速反馈信号减小,这时直流电动机的转速将___。
A. 降低
B. 升高
C. 不变
D. 不定
【单选题】
转速负反馈调速系统机械特性的硬度比电压负反馈调速系统机械特性的硬度 ___。
A. 硬
B. 软
C. 一样
D. 不变
【单选题】
晶闸管调速系统中, PI 调节器中的电容元件发生短路就会出现___。
A. 调速性能下降
B. 超速运行
C. 无法调速
D. 低速运行
【单选题】
为了保护小容量调速系统中的晶闸管不受冲击电流的损坏,在系统中应采用 ___。
A. 电压反馈
B. 电流正反馈
C. 转速负反馈
D. 电流截止负反馈
【单选题】
如果改变双闭环调速系统的速度,应该改变___参数。
A. 给定电压
B. 测速反馈电压
C. 速度调节器输出电压
D. 速度调节器输出限幅电压
【单选题】
双闭环调速系统在启动过程中调节作用主要靠___的作用。
A. P 调节器
B. I调节器
C. 速度调节器
D. 电流调节器
【单选题】
反馈控制只能使静差尽量减少,补偿控制___。
A. 不能消除静差
B. 有可能把静差完全消除
C. 只会使静差增大
D. 不管环境如何变化,都能把静差完全消除
【单选题】
电压负反馈调速系统通过稳定直流电动机电枢电压来达到稳定转速的目的,其原理是电枢电压的变化与___。
A. 转速的变化成正比
B. 转速的变化成反比
C. 转速变化的二次方成正比
D. 转速变化的二次方成反比
【单选题】
带有电流截止负反馈环节的调速系统,为了使电流截止负反馈参与调节后机械特性曲线下垂段更陡一些,应选择阻值___的反馈取样电阻。
A. 大一些
B. 小一些
C. 接近无穷大
D. 等于零
【单选题】
调速系统中,当电流截止负反馈参与系统调节时,说明调速系统主电路电流 ___。
A. 过大
B. 过小
C. 正常
D. 发生了变化
【单选题】
双闭环调速系统不加电流截止负反馈是因为___。
A. 由电流环保证
B. 由转速环保证
C. 由比例积分器保证
D. 由触发装置保证
【单选题】
自动控制系统中,反馈检测元件的精度对自动控制系统的精度___。
A. 有影响但被闭环系统完全补偿了
B. 有影响,无法补偿
C. 有影响但被闭环系统部分补偿了
D. 无影响
【单选题】
电压微分负反馈及电流微分负反馈是属于___环节。
A. 反馈环节
B. 稳定环节
C. 放大环节
D. 保护环节
【单选题】
电流正反馈主要补偿___上电压的损耗。
A. 电枢回路电阻
B. 电源内阻
C. 电枢电阻
D. 电抗器电阻
【单选题】
电动机在平衡状态时,电动机电枢电流的大小,主要取决于___。
A. 机械负载
B. 电枢电压和电枢内阻
C. 励磁磁通
D. 机械摩擦
【单选题】
无静差调速系统的调节原理是___。
A. 依靠偏差的积累
B. 依靠偏差对时间的积累
C. 依靠偏差对时间的记忆
D. 用偏差进行调节
【单选题】
交一交变频器仅适用于___。
A. 高速小容量
B. 低速小容量
C. 低速大容量
D. 高速大容量
【单选题】
直线感应同步器定子绕组是___。
A. 连续绕组
B. 分段绕组
C. 正弦绕组
D. 余弦绕组
【单选题】
由于变频器调速多应用于___电动机的调速,所以这种调速装置得到越来越广泛的应用。
A. 盲流
B. 步进
C. 笼型异步
D. 绕线转子异步
【单选题】
无源逆变器逆变的电压直接送给___。
A. 交流电源
B. 直流电源
C. 交流、直流电源均可
D. 负载
【单选题】
西门子 S7 系列可编程序控制器分为大、中、小型系统,以下___ 型号是小型机。
A. S7-400
B. S7-3 00
C. S7-200
D. s7-100
【单选题】
S7-200系列可编程序控制器 CPU22x 系列提供了不同的基本型号,以下___不是 CPu22x 系列基本型号。
A. CPU22O
B. CPU222
C. CPU224
D. CPU226
【单选题】
CPU22x 系列可编程序控制器具有 2 个 Rs-485 通信口的是___。
A. CPU221
B. CPU222
C. CPU224
D. CPU226
【单选题】
S7-200系列可编程序控制器 CPU22X 系列具有 1 个模拟电位器的是___。
A. CPU221
B. CPU224
C. CPU226
D. CPU226XM
【单选题】
CPU224 具有___个输入点。
A. 8
B. 10
C. 12
D. 14
【单选题】
CPU224 具有___个输出点。
A. 8
B. 10
C. 12
D. 14
【单选题】
PLC 内部在数据存储区为每一种元件分配一个存储区域,并用字母作为区域标志符,同时表示元件的类型。其中 T 表示___。
A. 变量存储器
B. 定时器
C. 计数器
D. 顺序控制存储器
【单选题】
区域标志符 C 表示___。
A. 变量存储器
B. 定时器
C. 计数器
D. 顺序控制存储器
【单选题】
可编程序控制器的编址就是对 PLC 内部的元件进行编码,字节编址中 1 个字节表示 ___位。
A. 4
B. 8
C. 16
D. 24
【单选题】
关于 PLC、下列观点正确的是___。
A. PLC 与变频器都可进行故障自诊断
B. PLC 的输人电路采用光藕合方式
C. PLC 的直流开关量输出模块又称为晶体管开关量输出模块,属无触点输出模块
D. 以上全正确
【单选题】
在 PLC 中,可以通过编程器修改或增删的是___。
A. 系统程序
B. 用户程序
C. 工作程序
D. 任何程序
【单选题】
PLC 编程时,输出线圈___。
A. 必须放在最左边
B. 必须放在最右边
C. 可放在任意位置
D. 可根据需要设置
【单选题】
关于 PLC 的功能,下列观点正确的是___。
A. PLC 具有强大的多种集成功能和实时特性
B. PLC 采用循环扫描工作方式
C. PLC 的抗干扰能力强,因此在工业控制中广泛采用
D. 以上全正确
【单选题】
57 一 oo 小型可编程序控制器的 CPU 在___部分。
A. 主机
B. FO 扩展单元
C. 功能单元
D. 外部设备
【单选题】
CPU224 型 PLC 的主机包括___。
A. 工作方式开关
B. FO 扩展接口
C. 工作状态指示
D. 以上都是
【单选题】
在程序中插人一个___指令, CPU 可由 RUN 方式进人 STOP 工作方式。
A. LD
B. AN
C. CUT
D. STOP
【单选题】
S7-200系列 PLC 的扩展单元没有___。
A. CPU
B. 输人接口
C. 输出接口
D. 状态指示