如果建网的目的只是提供连接和带宽,那么交换机只用老老实实地在数据链路层转发数据帧就是了。交换机在初级阶段确实是这么做的。但是,随着信息化建设进程的推进,用户网络中的各种应用越来越多,网络规模也越来越大,用户对网络的效率,安全、管理性等问题提出更高的要求,原有的纯粹二层交换机已经不能满足用户的实际需求。正因如此,实达网络公司于6月14日一举推出三大系列,八款产品的三层交换机。推动三层交换机规模应用的主要有四种因素。首先是用户网络应用的不断增多。在用户网络上传输的不再仅限于数据,网上交易、网上教学、视频点播、社区影院等日益成为用户对网络的现实需求。普通交换机在划分子网和广播限制等方面提供的控制非常少,极易造成网络拥塞,使数据包的丢失和延迟增加,服务质量无法保证。三层交换机则把网络通信中的二层交换技术和三层路由技术结合在一起,并通过 ASIC 技术达到线速交 If the purpose of building a network is simply to provide connectivity and bandwidth, then the switch will only forward data frames honestly at the data link layer. The switch did exactly that in the early stages. However, with the advancement of informatization construction, various applications in the user network are more and more and the network size is also getting larger and larger. Users have put forward higher requirements on the network efficiency, security and management issues. The original Some purely two switches can not meet the actual needs of users. Because of this, Shida network in June 14th launched in one fell swoop three series, eight products of the three switches. There are four main factors driving the three-tier switch scale application. The first is the growing number of user network applications. The user network is no longer limited to the transmission of data, online transactions, online teaching, video on demand, community cinema and other increasingly become the real needs of users of the network. Ordinary switches in subnet and broadcast restrictions and other aspects of the control provided very little, easily lead to network congestion, packet loss and delay increase, quality of service can not be guaranteed. Layer 3 switches then network communications in the second floor of the switching technology and the three-tier routing technology together, and through the ASIC technology to achieve line speed