一种基于SDN的分布式ARP代理方法

A Distributed ARP Proxy Approach in Software Defined Network

SDN(软件定义网络)有效地简化了网络的配置与管理,使网络的革新更加快捷。利用控制器作为ARP(地址解析协议)代理,能显著地减小数据层面的广播流量,缓解因广播带来的带宽资源浪费。然而,控制器多采用被动的方式下发流表,在处理大量的广播包时会产生极大的扩展性问题。文章提出了一种基于SDN的分布式ARP代理方法,将多个局域网的网关作为ARP代理,各局域网内部的ARP请求报文以单播的方式转发到其网关做统一处理。实验结果表明,该方法不仅大大减少了网络中的广播流量和ARP请求响应延时,而且极大地缓解了SDN控制器的负载,提高了SDN的扩展性。

The Software Defined Network （SDN） can provide simple and flexible network configuration and management. Re- cently, many proposals utilize the SDN controller as the Address Resolution Protocolproxy （ARP）, which obviously reduces the volume of broadcast flow in data plane and avoids the waste of bandwidth. However, since the recent controller has to use pro-active way to setup flow entries, it will cause the scalability problem when dealing with large amount of broadcast packets. Therefore, we propose a novel approach named Gater, which is a SDN-based distributed ARP proxy. Our approach uses the gateways as the ARP proxies, and they will respond to the ARP request in the corresponding LAN. According to the experi- mental results, our approach not only reduces the broadcast flow data in the network and the ARP response delay, but also lightens the payload of controller to achieve higher scalability.