单选题下图所示的网络拓扑中配置了 RIP 协议，且 RIP 协议已更新完成

单选题在VOIP 系统中，通过__（ ）__对声音信号进行压缩编码。

单选题 (66) is used to ensure the confidentiality, integrity and authenticity of the two end points in the private network. (67) , an application-layer protocol, authenticates each peer in an IPsec transaction. IKE negotiates security policy, determining which algorithm may be used to set up the tunnel. It also handles the exchange of session keys used for that one transaction. Networks that use (68) to secure data traffic can automatically authenticate devices by using (69) , which verify the identities of the two users who are sending information back and forth. IPsec can be ideal way to secure data in large networks that require secure connections among many devices. Users deploying IPsec can (70) their network infrastructure without affecting the applications on individual computer. The protocol suite is available as a software-only upgrade to the network infrastructure. This alows security to be implemented without costly changes to each computer. Most important, IPsec allows interoperability among different network devices, PCs and other computing systems.

单选题关于虚拟专用网，下面正确的语句是 （ ） 。

单选题Most IP layer-based proxy mechanisms, such as network address translation (NAT), only support uni-directional proxy, from the internal network to external network (the Internet). The proxy establishes the communication channel by (66) IP addresses. The IP addresses must be (67) . These proxy mechanisms prevent applications that must establish return data channels from establishing their data channels, such as, multimedia applications. IP layer-based proxy mechanisms need additional software (68) for each application that uses (69) channels. SOCKS identifies communication targets through domain names, overcoming the restriction of using private IP addresses. SOCKS can use domain names to establish communication between separate LANs, with (70) IP addresses.

单选题一名攻击者向一台远程主机发送特定的数据包，但是不想远程主机响应这个数据包。它采用的攻击手段可能是 (63) 。

单选题按照网络分级设计模型，通常把网络设计为3 层，即核心层、汇聚层和接入层，以下关于分级网络的描述中，不正确的是 （ ） 。

单选题活动目录(Active Directory)是由组织单元、域、 (39) 和域林构成的层次结构，安装活动目录要求分区的文件系统为 (40) 。

单选题Routing protocols use different techniques for assigning (71) to individual networks. Further, each routing protocol forms a metric aggregation in a different way. Most routing protocols can use multiple paths if the paths have an equal (72) Some routing protocols can even use multiple paths when paths have an unequal cost. In either case, load (73) can improve overall allocation of network bandwidth. When multiple paths are used, there are several ways to distribute the packets. The two most common mechanisms are per-packet load balancing and per-destination load balancing. Per-packet load balancing distributes the (74) across the possible routes in a manner proportional to the route metrics. Per-destination load balancing distributes packets across the possible routes based on (75)

单选题以下对几种网络管理工具/命令的描述中，错误的是______。 A．常见的网络数据监听工具有Sniffer Pro、Iris、TCPdump、Wireshark等 B．常用的漏洞扫描工具有ISS、MBSA、WSUS、X-Scanner等 C．tracert可以发现数据包到达目标主机所经过的路由器和到达时间 D．sniffer软件能够使网络接口处于杂收模式，从而可截获网络上传输的分组

单选题设信道带宽为3400Hz，采用PCM编码，采样周期为125μs，每个样本量化为256个等级，则信道的数据速率为______。

单选题一个主机的IP地址是172．16．2．12/24，该主机所属的网络地址是______。 A．172.0.0.0 B．172.16.0.0 C．172.16.2.0 D．172.16.1.0

单选题Microsoft's COM is a software architecture that allows applications to be built from binary software components. COM is the underlying (71) that forms the foundation for higher-level software services, like those provided by OLE. COM defines a binary standard for function calling between components, a way for components to dynamically discover the interfaces implemented by other components, and a mechanism to identify components and their interfaces uniquely. OLE is a compound (72) standard developed by Microsoft. OLE makes it possible to create (73) with one application and link or embed them in a second application. Embedded objects retain their original format and (74) to the application that created them. Support for OLE is built into the Windows and MacOS Operating Systems. A (75) compound document standard developed mainly by Apple and IBM is called OpenDoc.

单选题以下程序段违反了算法的{{U}} {{/U}}原则。 void sam() int n=2; while(!odd(n)) n+=2; printf(n); A．确定性 B．健壮性 C．有穷性 D．可靠性

单选题若一个单处理器的计算机系统中同时存在3个并发进程，则同一时刻允许占用处理器的进程数{{U}} (12) {{/U}}；如果这3个进程都要求使用2个互斥资源R，那么系统不产生死锁的最少的R资源数为{{U}} (13) {{/U}}个。

单选题要使Samba服务器在网上邻居中出现的主机名为smbserver，其配置文件smb．conf中应包含______。 A．workgroup=smbserver B．netbios name=smbserver C．server string=smbserver D．guest account=-smbserver

单选题为满足公司业务发展的需要，要求楼内综合布线系统为客户机提供数据速率为100Mb/s的数据、图像及语音传输服务，信息插座通常选用 (24) 。当布线结构需要调整时，可通过布线配线系统来重新配置，具体调整手段是通过 (25) 来实现的。