Cloud Computing is a use of computing resources that is delivered as a service over a network. Sharing the data in the cloud depends on the network performance of the data centers. Bandwidth allocation plays a major role in sharing the resources towards the data center networks. Server performance is the major problem in cloud computing. When multiple users send a request for the same server at a time, the performance of the server is considerably decreased. So we describe a novel method of reallocating the bandwidth dynamically from passive users to active users using bandwidth mutual sharing and fair sharing technique.