Distributed Component Object Model(DCOM).In process control,OLE and ProfiNet(OPC)use DCOM,which uses Microsoft’s Remote Procedure Call service.The service has many vulnerabilities,and many viruses will use this weakness to gain system privileges.In addition,OPC also uses DCOM to dynamically open arbitrary ports,which is very difficult to filter in firewalls.The general firewall cannot complete the rules and restrictions on the OPC protocol.If the protocol is required,the control network and the network must be physically separated,and the control network and the enterprise network must be separated horizontally.
分布式组件对象模型(DCOM)。在过程控制中,OLE和ProfiNet(OPC)是使用DCOM的,它运用了微软的远程过程调用服务。该服务有很多的漏洞,很多病毒都会利用这个弱点获取系统权限。此外OPC也利用DCOM动态地打开任意端口,这在防火墙中进行过滤是非常困难的。通用防火墙无法完成对OPC协议的规则限制,如果必须需要该协议,则要求控制网络、网络之间必须物理分开,将控制网络和企业网络横向隔离。
HP/Agilent 83630B/SN:3844A00121 Synthesized Swept-Signa
HP/Agilent 83630B Synthesized Swept-Signal Generator,10
HP/Agilent 5071A Primary Frequency Standard
HP/Agilent E4438C ESG Vector Signal Generator,250 KHz t
HP/Agilent E4407B/SN:MY45108122 ESA-E Spectrum Analyzer
HP/Agilent E4407B ESA-E Spectrum Analyzer, 9 KHz – 26.5