Then it studies the network vulnerability scanning technology, witch includes port scanning, vulnerability scanning and dictionary attacking.

而对目标系统漏洞信息的获取，目前主要是通过网络漏洞扫描工具实现的。

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IaaS providers may not allow network-based vulnerability scanning because they have no way of distinguishing friendly network scans from attack activity.

IaaS提供商可能不允许基于网络的漏洞扫描，因为他们无法区分善意的网络扫描和攻击活动。

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Also, standard tech-niques such as network-based vulnerability scanning are usually forbidden by IaaS providers because, for example, friendly scans can't be distinguished from at-tacker activity.

此外，标准的技术，如基于网络的漏洞扫描通常被IaaS提供商所禁止，原因之一是无法把友好的扫描从攻击者的活动区别开来。

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