ARP virus has a strong impact on college network working. The present protection systems either can partially defend ARP virus or cost a lot. Based on the characteristics of three OSS such as Nediva, FreeRadius and ZeroShell on www.sf.net, this article designs an ARP virus protection system which doesn't depend on exchange hardware of specific brand and model. The innovation of this protection system is reflected in blockading and dredging the virus-infected machine automatically, which has nothing to do wi...