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1.
王运军 《科教文汇》2008,(1):193-194
随着Internet的飞速发展,越来越多的用户加入到互联网的使用中。现在互联网仍广泛采用IPv4技术,IP地址即将耗尽。在IPV6尚未实施时,解决IP地址资源的最有效的过渡办法就是采用NAT(网络地址转换)技术。虽然NAT技术暂时缓解了IP地址短缺问题,但经过IP转换,因更改了IP包报头,网络互联出现较多问题,部分情况下无法满足供电企业实际应用系统直通互联需求。笔者在网络管理实践中,通过对NAT技术的改进,采用公私IP地址混用技术,即解决了IP地址短缺问题,又解决了与上级公司直通互联问题。  相似文献   

2.
为解决IPV4地址资源紧张问题,NAT技术应运而生。NAT技术将内网的私有地址转换为外网的公有地址,从而实现和Internet用户的通信,在解决IP地址不足问题的同时,隐藏了内部网络的细节,防止了部分来自网络外部的攻击,具有一定的安全作用。由于NAT技术的复杂多样性,造成复杂网络中应用的复杂性,NAT技术的综合使用要兼顾内外网各种要素,周密计划,严密组织,避免网络漏洞,对此进行了论述。  相似文献   

3.
随着国际互联网在中国的普及,国际互联网用户与日俱增。面临的主要问题是IP地址即将耗尽,而NAT是解决目前IP地址资源紧缺的主要技术。本文着重简述利用Windows2003操作系统来配置NAT。  相似文献   

4.
余明华 《大众科技》2005,(10):72-73
NAT是将私有IP地址转换成外部的公共IP地址的映射方式.在合法IP地址缺乏的情况下,使用路由器(具有NAT模块) 交换机的做法无疑是一个好的选择,但使用服务器来实现NAT功能则更能体现出其技术上的优越性.  相似文献   

5.
随着上网用户的不断增加,对IP的需求越来越大,NAT技术在一定程度上解决了IPv4地址不足的问题,本文提出了一种研究NAT技术的方案,即利用Packet Tracer仿真软件模拟实际的公私网地址的转换,分析NAT技术的转换过程、效果。通过搭建网络,一方面熟悉网络设备及连线基本特征;另一方面,加深理解动态NAT、静态NAT、NAPT、DHCP、DNS等网络技术。  相似文献   

6.
张海峰 《内江科技》2007,28(6):106-107
网络地址转换(NAT)技术的应用,不仅成功缓解了当前世界上的IP地址短缺问题,而且作为防火墙可以为企业内部网提供对外的屏蔽.由于其禁外网主机主动访问内网主机,这就为位于不同NAT后的主机之间实现P2P通信带来了困难.文中提出通过一台公网服务器,利用UDP来穿透NAT实现P2P通信的解决方案.  相似文献   

7.
《内江科技》2016,(2):60-61
目前Internet上的主机都必须使用唯一的IP地址,因此常会面临IP地址不足的窘况。除此之外,它也会产生安全性问题,因为直接暴露在Internet的主机都将遭受来自外界的攻击。有鉴于此,本文将尝试使用NAT的方式来提供解决方案,同时也介绍Linux下iptables软件的使用和防火墙的基本概念。  相似文献   

8.
温卫  陈丰 《科技广场》2006,(5):51-52
本文阐述NAT和PVLAN的工作原理,并通过实际模型的案例分析,介绍了解决校园网IP地址短缺的方法,提高了IP地址的利用率.  相似文献   

9.
司治纲 《科技风》2011,(3):195+213
中心局域网出现中断现象,经对故障现象的分析处理和试验,采用防火墙系列产品,解决了IP地址冲突趋式的中心局域网瘫痪问题,基本上遵循了以前IP地址的原则,在网络及IP分配方案基本没有改动的基础上解决了问题。  相似文献   

10.
《情报探索》2006,(5):128-128
灵活的网络地址转换黑盾防火墙采用双向网络地址转换(双向NAT)技术,支持静态NAT及动态NAT,并能够实现一对一、一对多的地址映射,并可以对外部地址提供针对主机的地址映射和针对服务的端口映射,确保局域网内部通讯安全。细粒度访问控制功能黑盾防火墙采用基于地址、协议、端口、流量的访问控制  相似文献   

11.
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China's science enterprise by making S&T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party's Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.  相似文献   

12.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

13.
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."  相似文献   

14.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

15.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

16.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

17.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

18.
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.  相似文献   

19.
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.  相似文献   

20.
Prof. SUN Changpu from the CAS Institute of Theoretical Physics and coworkers from University of Basel in Switzerland have worked out a way --at least in theory --to split a beam of molecules according to their chirality. The technique involves passing the molecules through three different laser beams and is similar to the famous Stern-Gerlach effect, whereby a beam of atoms passing through a magnetic field is split in two according to the atoms' spin states (Phys. Rev. Lett. 99 130403).  相似文献   

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