A data center is a pool of resources (computational, storage, network) interconnected using a. A data center network (DCN) holds a pivotal role in a , as it interconnects all of the data cent. A data center is a pool of resources (computational, storage, network) interconnected using a. A data center network (DCN) holds a pivotal role in a, as it interconnects all of the data center resources together. DCNs need to be scalable and efficient to connect tens or even hundreds of thousands of servers to handle the growing demands of. Today's data centers are constrained by the interconnection network. The three-tier DCN architecture follows a multi-rooted composed of three layers of network switches, namely access, aggregate, and core layers. The in the lowest layers are connected directly to one of the edge layer switches. The aggregate layer switches interconnect together multiple access layer switches. All of the aggregate layer switches are connected to each other by core layer switches. Core layer switches are also responsible for connecting the data center to the. The three-tier is the common network architecture used in data centers. However, three-tier architecture is unable to handle the growing demand of cloud computing. The higher layers of the three-tier DCN are highly oversubscribed. Moreover, scalability is another major issue in three-tier DCN. Major problems faced by the three-tier architecture include, scalability,, energy efficiency, and cross-sectional bandwidth. The three-tier architecture uses enterprise-level network devices at the higher layers of topology that are very expensive and power hungry. The fat tree DCN architecture reduces the oversubscription and cross section bandwidth problem faced by the legacy three-tier DCN architecture. Fat tree DCN employs commodity network switches based architecture using. The network elements in fat tree topology also follows hierarchical organization of network switches in access, aggregate, and core layers. However, the number of network switches is much larger than the three-tier DCN. The architecture is composed of k pods, where each pod contains, (k/2) servers, k/2 access layer switches, and k/2 aggregate layer switches in the topology. The core layers contain (k/2) core switches where each of the core switches is connected to one aggregate layer switch in each of the pods. The fat tree topology can offer up to 1:1 oversubscription ratio and full, depending on each rack's total bandwidth versus the bandwi. Scalability is one of the foremost challenges to the DCNs. With the advent of cloud paradigm, data centers are required to scale up to hundreds of thousands of nodes. Besides offering immense scalability, the DCNs are also required to deliver high cross-section bandwidth. Current DCN architectures, such as three-tier DCN offer poor cross-section bandwidth and possess very high over-subscription ratio near the root. Fat tree DCN architecture delivers 1:1 oversubscription ratio and high cross section bandwidth, but it suffers from low scalability limited to k=total number of ports in a switch. DCell offers immense scalability, but it delivers very poor performance under heavy network load and one-to-many traffic patterns. A quantitative analysis of the three-tier, fat tree, and DCell architectures for performance comparison (based on throughput and latency) is performed for different network traffic pattern. The fat tree DCN delivers high throughput and low latency as compared to three-tier and DCell. DCell suffers from very low throughput under high network load and one to many traffic patterns. One of the major reasons for DCell's low throughput is very high over subscription ratio on the links that interconnect the highest level cells. The DCell exhibits very high robustness against random and targeted attacks and retains most of its node in the giant cluster after even 10% of targeted failure. multiple failures whether targeted or random, as compared to the fat tree and three-tier DCNs. One of the major reasons for high robustness and connectivity of the DCell is its multiple connectivity to other nodes that is not found in fat tree or three-tier architectures.