Data centers today are facing increasing challenges due to virtualization and explosive growth in end-user devices. Geographic expansions are adding another level of complexity to the data center networking management. In addition to virtualization, cloud computing, and consolidation, security is also another biggest concern for data center operators, as legacy data center network consists of a patchwork of specialized security appliances that are complex and even difficult to manage and scale. The old device-centric security model makes it difficult to adapt to evolving threats and embrace new technologies such as Software-as-a-Service (SaaS) and virtualization. To address these demands, leading vendors such as Cisco, Juniper Networks, Brocade, and others are offering data center solutions that consolidate and simplify the security measurements, making data centers more secure and agile.