Abstract: Network layer is the third layer in the OSI model . The network layer provides connectivity and path selection between two host systems. It is responsible for routing data packets and selecting the best path to deliver data. The network layer prioritizes data known as Quality of Service (QOS) . Routers  and Layer 3 switches operate at the network layer. A Router can also act as a Layer 2 and Layer 1 device. A routing protocol  specifies how routers communicate with each other. A routing protocol is a set of rules used by routers to determine the most appropriate path into which they should forward packets towards their intended destination. In this paper we give you a brief introduction on redistribution. Using a routing protocol to advertise routes that are learned by some other means, such as by another routing protocol, static routes or directly connected routes, is called redistribution. This situation never arises in the case of single protocol routing environment but multi-protocol routing is common for a number of reasons like company mergers, multiple departments managed by multiple network administrators, and multi-vendor environments. Route redistribution allows different routing protocols to exchange routing information. In this paper we have considered one such situation of route redistribution. Redistribution is done at the boundary routers at the boundary of two merged companies- company A and company B, adapting OSPF and EIGRP routing protocols respectively in their respective AS.
Keywords: Network layer, OSI model, Quality of Service (QOS), Routers and Layer 3 switches, multi-protocol routing, redistribution, OSPF and EIGRP.