Definition
Enhanced Interior Gateway Routing Protocol EIGRP is a hybrid routing protocol that combines features of distance vector and link state routing protocols. It dynamically exchanges routing information between routers to determine the best paths for data packets across a network. EIGRP uses a sophisticated algorithm called the Diffusing Update Algorithm DUAL to calculate loop free paths and ensure rapid convergence when network changes occur. This protocol is crucial for maintaining efficient and reliable network communication, especially in large and complex enterprise environments. For instance, a network administrator might configure EIGRP on Cisco routers to manage traffic flow between different departments in a company. It is important to distinguish EIGRP from simpler distance vector protocols like RIP, as EIGRP offers more advanced features and scalability. You will encounter EIGRP concepts on networking certifications such as CCNA and in discussions of routing protocols on security exams.