中文摘要：

网络试验床作为模拟实际环境进行大量测试和验证性实验的开发平台,对增强网络技术自主创新能力与网络安全能力至关重要.虚拟网络构建是指在试验床上快捷准确地完成实验网络环境搭建.文章首先详细介绍了虚拟网络构建中基于图形界面和基于配置文件的两种网络拓扑生成方式;然后针对有限物理资源下支持更大的实验场景或支持更多的并发实验,提出虚拟网络构建的可伸缩性支持,并对可伸缩性的实现方案进行了详细阐述;最后介绍了在网络试验床上进行DDoS攻击实验的虚拟网络构建和可伸缩性调整流程.

英文摘要：

Network testbed as development platform that simulates the real-world environment for running extensive tests and validation experiments, it＇s essential to enhance capability of independent innovation for network technology and capability of network security. Firstly, this paper introduces two topology generation methods in the virtual network construction： based on graphical interface and based on conifguration ifle. Then, for supporting larger test scenarios or more concurrent tests under limited physical resources, this paper proposes to build a virtual network which has scalability, and describes the implementation scheme of scalability in detail. Finally, this paper introduces the virtual network construction and scalability adjustment process when executes DDoS attack test in the network testbed.