首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
While hackers with motives make headlines, they represent less than 20% of all net- work security breaches. More common are inst
While hackers with motives make headlines, they represent less than 20% of all net- work security breaches. More common are inst
admin
2013-01-29
55
问题
While hackers with motives make headlines, they represent less than 20% of all net- work security breaches. More common are instances of authorized users accidentally winding up where they should not be and inadvertently deleting or changing data. However, the Internet introduces another concern: some Internet surfers are bound to go where they have no business and, in so doing, threaten to wipe out data to which they should not have access.
Before picking a firewall, companies need to adopt security policies. A security policy states who or what is allowed to connect to whom or what. You can group all users by department or classification. The better firewall products let you drag and drop groups in a graphical user interface (GUI) environment to define network security easily.
Two methods are most often used together to establish an Internet firewall. They are application and circuit gateways, as well as packet filtering. With application and circuit gateways, all packets are addressed to a user-level application on a gate-way that relays packets between two points. With most application gateways, additional packet-filter machines are required to control and screen traffic between the gateway and the networks. A typical configuration includes two routers. With a bastion host that serves as the application gateway sitting between them.
A drawback to application and circuit gateways is that they slow network performance. This is because each packet must be copied and processed at least twice by all the communication layers. Packet-filter gateways, which act as routers between two nets, are less secure than application gateways but more efficient. They are transparent to many protocols and applications, and they require no changes in client applications, no specific application management or installation, and no extra hardware.
Using a single, unified packet-filter engine, all net traffic is processed and then for- warded or blocked from a single point of control. However, most packet filters are state- less, understand only low-level protocols, and are difficult to configure and verity. In addition, they lack audit mechanisms. Some packet filters are implemented inside routers, limiting computing power and filtering capabilities. Others are implemented as s9ftware packages that filter the packets in application-layer processes, an inefficient approach that requires multiple data copies, expensive delays and context switches and delivers lower throughput.
So what’s a network administrator to do? Some vendors are developing firewalls that overcome many of these problems and combine the advantages of application gateways and packet filtering. These efficient, protocol-independent, secure firewall engines are capable of application-level security, user authentication, unified support, and handling of all protocols, auditing and altering. They are transparent to users and to system setup, and include a GUI for simple and flexible system management and configuration.
For whom is this passage most likely written?
选项
A、Government officials.
B、Hackers.
C、Network. administrators.
D、Computer experts.
答案
C
解析
本题考查文章的读者对象。很显然作者对网络防火墙的分析以及提出的建议都是针对网络管理者的。政府官员、黑客和计算机专家也可能阅读本文,但相比而言,不是最直接的读者对象。
转载请注明原文地址:https://jikaoti.com/ti/9RqYFFFM
0
考博英语
相关试题推荐
Unlikemostsports,whichevolvedovertimefromstreetgames,basketballwasdesignedbyonemantosuitaparticularpurpose.
Battlesarelikemarriages.Theyhavecertainfundamentalexperiencetheyshareincommon;theydifferinfinitely,butstillthe
CarlyFiorina,Hewlett-Packard’schiefexecutive,cameoutfightingonNovember14th.Inaconferencecallwithanalysts,shean
____throughtheatticandseeifyoucanfindanythingforthejumblesale.
JanHendrikSchon’ssuccessseemedtoogoodtobetrue,anditwas.InonlyfouryearsasaphysicistatBellLaboratories,Scho
JanHendrikSchon’ssuccessseemedtoogoodtobetrue,anditwas.InonlyfouryearsasaphysicistatBellLaboratories,Scho
Debbieisadivorceewholiveswithherchildren.Sheworksinadoctor’sofficeandenjoysthecontactwithpeople.Herson,J
Medicalconsumerism--likeallsortsofconsumerism,onlymoremenacingly--isdesignedtobesatisfying.【51】Theprolongationofl
Ihavehadjustaboutenoughofbeingtreatedlikeasecond-classcitizen,simplybecauseIhappentobethatput-uponmemberof
In1784,fiveyearsbeforehebecamepresidentoftheUnitedStates,GeorgeWashington,52,wasnearlytoothless.Sohehireda
随机试题
国际促销的主要形式可以划分为()
脑膜中动脉发自()
端粒酶可看作是一种
患儿超声检查见左上腹巨大实性肿块,边界尚清,内部回声不均,与左肾关系密切,并见肾脏积水。可能的诊断是
患者,男,28岁。低热、咳嗽2个月,痰中带血1周,血色鲜红,午后潮热,五心烦热,骨蒸颧红,盗汗量多,形体日渐消瘦,舌红绛而干,苔黄,脉细数。查体:体温37.6℃,双侧颈后可触及多个活动淋巴结,右上肺可闻及支气管肺泡呼吸音,胸部X线显示右上肺斑点状阴影。
男性,34岁,因急性阑尾炎穿孔伴局限性腹膜炎,行阑尾切除术后5天,仍有腹痛,腹胀,体温38℃以上,大便3~5次/天,有下坠感。血WBC18×19/L。为明确诊断.首先应做的检查是
心脏瓣膜病变最常见的心律失常为
已设立的股份有限公司增加资本,申请发行境内上市外资股时,公司净资产总值不低于1亿元人民币。()
《党政机关公文处理工作条例》中按照公文处理的工作流程将公文处理工作概括为三个相互关联、衔接有序的工作环节,不包括()。
把下面的六个图形分为两类,使每一类图形都有各自的共同特征或规律,分类正确的一项是:
最新回复
(
0
)