Putting in more security measures and access controls within an organisation runs contrary to operational e ciency and convenience. Although the balance between security and operational e ciency is critical to making the combination works for the better, most administrators will rather forego security than performance if either has to be traded o . To address this problem, we propose a complementary infrastructure to manage and monitor the existing network. This infrastructure is called the Shadow Netowrk Management System (SNMS). It integrates seamlessly with the network infrastructure without degrading network performance and user convenience. The underlying paradigm is one of making it possible for security and operational e ciency to co-exist, rather than trading o one for the other. We show that SNMS can provide the necessary assurance to prevent intra-network misuse without a ecting the ow of network tra c and access.