体系结构

因可预见或不可预见的甚至是恶意的原因而遭到破坏，更改、泄露或功能失效，使信息系统处于异常状态，甚至引起系统的崩溃瘫痪，造成巨大的经济损失。 在这样的形势下，以保护网络中的信息免受各种攻击为根本目的网络安全变得越来越重要。 计算机网络改变着人们赖以行动的社会信息结构，改变着人们获取利用信息的方式，从而引起人类生活方式的全面改观。 网络安全威胁一般分为外部闯入、内部渗透和不当行为三种类型。

ucture of C/S. C/S ( Client/Server ) structure, the server structure and client puter that all know well. It is software systematic architecture, through it can hold hardware environment fully using

d of structure has solved traditional Client/Server can expand problem, have reduced customer end business logic , and have reduced the requirement of customer end for hardware. At the same time

the use of flexible buffer sizes. Catalyst 5000 Ether line card port buffer memory is flexible and can create frame buffers for any frame size, making the most of the available buffer memory.