单选题SNMP报文中不包括（ ）。
单选题定级备案为等级保护第三级的信息系统。应当每（ ）对系统进行一次等级测评。
单选题某公司中，最大的局域网可容纳200个主机，最小的局域网可容纳20个主机，若使用可变长子网掩码划分子网，其最长的掩码作答此空 位， 最短的掩码 位。
单选题Network frewalls are security devices used to stop or mitigate () access to private networks connected to the Internet, especially intranets. The only trafle alowed on thev network is defined via firewall (回答此处 )-any other taff attempting to access the network is blockeD. Network firewalls sit at the ( ) line of a network, acting as a communicationsliaison between intemal and gxtemal devics, When properly configured, a firewall alws users to access any of the resources they need while simultaneously keeping out unwanted accesses. In addition to limiting access to a protected computer and network, a firewall can ( ) all traffit coming into or leaving a network, and manage remote access to a private network through secure authentication grtificates and logins. ( ) firewalls examine every packet that passes through the network and then accep or deny it as defined by rules set by the user.
单选题数据包通过防火墙时，不能依据（ ）进行过滤。
单选题在 OSI 参考模型中，（）在物理线路上提供可靠的数据传输服务。
单选题lA network attack is an attempt to gain（）access to an organization’s network,with the objective of stealing data or performing other malicious activities.Plagiarism is A（）-of-service（DoS）attack is a cyber-attack in which the attacker seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network.In the case of a simple attack,a（）could have a simple rule added to deny all incoming traffic from the attackers,based on protocols,ports,or the originating IP addresses.In a（）DoS（DDoS）attack ，the incoming traffic flooding the victim originates from（作答此空）different sources.This effectively makes it impossible to stop the attack simply by blocking a single source.
单选题企业信息化的作用不包括（ ）。
单选题设信道带宽为5000Hz，采用PCM编码，采样周期为125gs，每个样本量化为256个等级
单选题路由器的(58)________________接口通过光纤连接广域网。
单选题RIP 路由协议是一种基于(回答此处 )为度量的路由协议，其中RIPv1使用广播方式来进行路由更新，RIPV2使用组播方式来进行路由更新，其组播地址是( )。
单选题某主机的MAC地址为00-FF-12-CD-10-22，其IP地址配置选项设置为“自动配置”，该主机可通过发送( )报文以查找DHCP服务器，并请求IP地址配置信息，报文的源MAC地址是( )，源IP地址是(回答此处 )。
单选题采用n位补码(包含一个符号位)表示数据，可以直接表示数值(1)________________。
单选题Python 语言的特点不包括 。
单选题lA network attack is an attempt to gain（）access to an organization’s network,with the objective of stealing data or performing other malicious activities.Plagiarism is A（）-of-service（DoS）attack is a cyber-attack in which the attacker seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to a network.In the case of a simple attack,a（作答此空）could have a simple rule added to deny all incoming traffic from the attackers,based on protocols,ports,or the originating IP addresses.In a（）DoS（DDoS）attack ，the incoming traffic flooding the victim originates from（）different sources.This effectively makes it impossible to stop the attack simply by blocking a single source.
单选题下列功能模块中，不属于操作系统内核功能模块的是（ ）。
单选题假设一个IP数据报总长度为3000B，要经过一段 MTU为1500B的链路，该P数据报必须经过分片才能通过该链路。该原始IP数据报需被分成（ 此空作答 ）个片，若IP首部没有可选字段，则最后一个片首部中Offset字段为（ ）。
单选题某主机的MAC地址为00-FF-12-CD-10-22，其IP地址配置选项设置为“自动配置”，该主机可通过发送( )报文以查找DHCP服务器，并请求IP地址配置信息，报文的源MAC地址是(回答此处 )，源IP地址是( )。
单选题TCP伪首部不包含的字段为（ ）。
单选题以下关于 IPv6 与 IPv4 比较的说法中，错误的是（）。