In the big data era, the principal traffic bottleneck in a data center is the communication between hosts. Moreover, the redundant packet contents indeed take a major part of the bottleneck. In this paper, we propose a distributed and efficient cache sharing protocol, named DCP, to eliminate redundant traffic in data center with Fat-Tree topology. In DCP, each switch holds packet caches, which are used for eliminating redundant packets. A cache sharing mechanism using Bloom Filter is also proposed to share local caches of switches with servers. Moreover, we propose another technique leveraging Bloom Filter to reduce false positive ratio caused by sharing cache information between switches and servers. We build up a Fat-Tree topology with k = 16 to evaluate the performance of DCP, and the simulation results show that DCP can eliminate 40% to 60% redundant packets, which validate its efficiency.