局域网毕业论文文献翻译中英文对照.doc

1、 外文资料及中文译文院系名称 信息科学与技术学院 学生姓名 学生学号 _ 200503013098 专业班级 _ 计科03- 7 指导教师 10外文资料出处：计算机世界报 第03期 C20A LAN may be created based on a peering or a client-server. Small LANs are of ten created based on a simple peering relationship. Users may share resources and communicate with one another on a peer network

2、, but no single computer controls a peer network, and peer network users do not typically centralize files on one machine. As a rule, peer networks tend to lack organization and adequate security controls.The client-server architecture is usually used for sever controls network access and network re

3、sources. Clients request resources from the server, and the server provides resources to clients. Servers may range in complexity from mainframes to PCs. Clients may range in complexity from PCs to display to terminals (DTS). Client-Server networks provide strong central security, centralized file o

4、rganization and storage, and centralized data preservation. Compared to a peer network, a client-server network requires more centralized and specialized administration.Along with the rapid scientific and technological development, computer use in production as a proportion growing, increasingly pla

5、y a decisive role in the ministry, the office has computers, greatly facilitate the departments work, another demand gradually reveal themselves. That is the single transmission of information between. Computer networks should be established as soon as possible on the agenda. Establish computer netw

6、orks main purpose is to realize a resource sharing that all network users can enjoy the computer systems of all or part of the resources.LAN are currently used to broadcast the technical basis for Ethernet, any two nodes of communication between the data packet is not only these two nodes by the car

7、d receipt, were also at the same Ethernet to the nodes of a network card by the interception, As long as hackers access to the Ethernet nodes for an interception, can capture the Ethernet in the data packet and all its packet analysis solution, thereby stealing critical information, This is the Ethe

8、rnet inherent security risks. In fact, many on the Internet free of the hacking tools are put Ethernet interception as the most fundamental means. A firewall is a network device that enforces security policy for network traffic. The term originates from firewall, a fireproof wall used as a barrier t

9、o prevent the spread of fire. An Internet firewall creates a barrier between separate networks by imposing a point of control that traffic needs to pass before it can reach a different network. A firewall may limit the exposure of hosts to malicious network traffic, e.g., remote adversaries attempti

10、ng to exploit security holes in vulnerable applications, by preventing certain packets from entering networks protected by the firewall.When inspecting a network packet, a firewall decides if it should drop or forward the packet. The decision is based on a firewalls security policy and its internal

11、state. Before forwarding a packet, a firewall may modify the packets content. Packet inspection may occur at several different layers: (1)The link layer provides physical addressing of devices on the same network. Firewalls operating on the link layer usually drop packets based on the media access c

12、ontrol (MAC) addresses of communicating hosts. (2)The network layer contains the Internet protocol (IP) headers that support addressing across networks so that hosts not on the same physical network can communicate with each other. (3)The transport layer provides data flows between hosts. On the Int

13、ernet, the transmission control protocol (TCP) and the user datagram protocol (UDP) are used for this purpose. Most firewalls operate at the network and transport layer. TCP provides reliable data flow between hosts. UDP is a much simpler but unreliable transport protocol. (4)The application layer c

14、ontains application specific protocols like the hypertext transfer protocol (HTTP). Inspection of application specific protocols can be computationally expensive because more data needs to be inspected and more states are required. A firewall is a piece of software or hardware that helps screen out

15、hackers, viruses, and worms that try to reach your computer over the Internet. If you are a home user or small-business user, using a firewall is the most effective and important first step you can take to help protect your computer. It is important to have a firewall and antivirus software turned on before you connect to the Internet. If your computer is not protected when you connect to