Policy-Based Routing in RIP-Hybrid Network with SDN Controller

Software defined networking (SDN) is a new architecture for computer networks in which control plane is decoupled from data plane and is implemented centrally. Entrance of SDN in companies requires upgrade of legacy network equipment which will have high costs for the company. The solution to this problem is gradual deployment of SDN in form of hybrid networks. Hybrid networks necessitate communication between control plane of legacy devices and the SDN controller. This communication helps to use SDN capability in hybrid networks. In legacy networks, policy-based routing (PBR) is a mechanism used to make routing decisions based on the policies set by the network administrators and provides a flexible mechanism for routing. In this paper, we introduced a new method for policy-based routing (PBR) in RIP-based hybrid networks by using SDN controller and OpenFlow protocol. In this method, the OpenFlow switches send advertisement packets with fake metrics towards the legacy routers. With this procedure we can change the routing table of legacy router based on the controller’s policies.