题目：【问题1】(8分)请简要分析该网络接入层的组网特点(优点及缺点各回答2点)。

题目：An advanced persistent threat (APT) is a covert (71) attack on a computer networkwhere the attacker gains and maintains (72)access to the targeted network and remains undetected for a significant period. An APT is a sophisticated,long-term and (73) attack,usually orchestrated by nation-state groups，or well-organized criminal enterprises. Duringthe time between infection and remediation the hacker will often monitor，intercept，and relayinformation and sensitive data. The intention of an APT is usually to (74) or steal datarather than cause a network outage，denial of service or infect systems with malware.APTsoften use social engineering tactics or exploit security (75)in networks，applications orfiles to plant malware on target systems.A successful advanced persistent threat can beextremely effective and beneficial to the attacker.

题目：An advanced persistent threat (APT) is a covert (71) attack on a computer networkwhere the attacker gains and maintains (72)access to the targeted network and remains undetected for a significant period. An APT is a sophisticated,long-term and (73) attack,usually orchestrated by nation-state groups，or well-organized criminal enterprises. Duringthe time between infection and remediation the hacker will often monitor，intercept，and relayinformation and sensitive data. The intention of an APT is usually to (74) or steal datarather than cause a network outage，denial of service or infect systems with malware.APTsoften use social engineering tactics or exploit security (75)in networks，applications orfiles to plant malware on target systems.A successful advanced persistent threat can beextremely effective and beneficial to the attacker.

题目：An advanced persistent threat (APT) is a covert (71) attack on a computer networkwhere the attacker gains and maintains (72)access to the targeted network and remains undetected for a significant period. An APT is a sophisticated,long-term and (73) attack,usually orchestrated by nation-state groups，or well-organized criminal enterprises. Duringthe time between infection and remediation the hacker will often monitor，intercept，and relayinformation and sensitive data. The intention of an APT is usually to (74) or steal datarather than cause a network outage，denial of service or infect systems with malware.APTsoften use social engineering tactics or exploit security (75)in networks，applications orfiles to plant malware on target systems.A successful advanced persistent threat can beextremely effective and beneficial to the attacker.

题目：An advanced persistent threat (APT) is a covert (71) attack on a computer networkwhere the attacker gains and maintains (72)access to the targeted network and remains undetected for a significant period. An APT is a sophisticated,long-term and (73) attack,usually orchestrated by nation-state groups，or well-organized criminal enterprises. Duringthe time between infection and remediation the hacker will often monitor，intercept，and relayinformation and sensitive data. The intention of an APT is usually to (74) or steal datarather than cause a network outage，denial of service or infect systems with malware.APTsoften use social engineering tactics or exploit security (75)in networks，applications orfiles to plant malware on target systems.A successful advanced persistent threat can beextremely effective and beneficial to the attacker.

题目：An advanced persistent threat (APT) is a covert (71) attack on a computer networkwhere the attacker gains and maintains (72)access to the targeted network and remains undetected for a significant period. An APT is a sophisticated,long-term and (73) attack,usually orchestrated by nation-state groups，or well-organized criminal enterprises. Duringthe time between infection and remediation the hacker will often monitor，intercept，and relayinformation and sensitive data. The intention of an APT is usually to (74) or steal datarather than cause a network outage，denial of service or infect systems with malware.APTsoften use social engineering tactics or exploit security (75)in networks，applications orfiles to plant malware on target systems.A successful advanced persistent threat can beextremely effective and beneficial to the attacker.

题目：小张为A公司承建的SU大学新校区的网络建设项目的负责人，B公司以较低价格获得该项目所有网络设备供应权，设备采购合同约定B公司设备到场后，A公司一次性支付设备款项。项目试运行后，网络系统故障不断，无法达到项目要求，A公司又更换部分设备后，才基本解决问题。经过估算，该项目最终利润可能是负值，没有达到预计经济目标。造成该结果的主要原因是(70）。

题目：培训教室安装有120台终端电脑和3台48口千兆以太网交换机，3台交换机依次级联，终端电脑通过5类非屏蔽双绞线连接交换机，双绞线和电源线共用防静电地板下的线槽从机柜敷设到各终端电脑处。安装完成后培训教室内的电脑相互ping测试，发现时有丢包现象，丢包率约1~2%，造成该现象的原因可能是(69)。

题目：启夏公司网络管理员小王在例行巡查时，发现某存储系统的5号磁盘指示灯为红色，造成红色指示灯亮的主要原因可能是（1）应该采取（2）措施处置。

题目：启夏公司网络管理员小王在例行巡查时，发现某存储系统的5号磁盘指示灯为红色，造成红色指示灯亮的主要原因可能是（1）应该采取（2）措施处置。