随着企业网络规模的不断扩大，网络结 构显得越来越重要，网络结构的优劣直接关系到整个网络的性能和扩展性。 企业网络需要采用模块化的层次网络设计方法。层次网络设计可以为企业网络带来很多益处，一方面可以提供先进的扩展性、容错可靠性、网络流量的可预见性以及高效性， With the continuous expansion of the size of the enterprise network, the network structure is more and more important. The quality of the network structure is directly related to the performance and scalability of the entire network. Enterprise networks need to adopt a modular, hierarchical network design approach. Hierarchical network design can bring many benefits to enterprise networks, while providing advanced scalability, fault-tolerant reliability, predictability of network traffic, and high efficiency,