Enhanced Interior Gateway Routing Protocol


Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco proprietary advanced distance-vector routing protocol. It is used on a computer network for automating routing decisions and configuration. EIGRP incorporates features of both link-state and distance-vector protocols, offering more robustness and flexibility.


The phonetics of the keyword ‘Enhanced Interior Gateway Routing Protocol’ would be:Enhanced: /ɪnˈhanst/Interior: /ɪnˈtɪər.i.ɔːr/Gateway: /ˈɡeɪt.weɪ/Routing: /ˈruːtɪŋ/ or /ˈraʊtɪŋ/Protocol: /ˈproʊ.tə.kɑːl/

Key Takeaways

  1. Advanced Distance Vector Protocol: Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance vector protocol that, unlike other routing protocols, considers multiple factors (bandwidth, load, delay, and reliability) for routing the packets, not just hop count.
  2. Routing Updates: EIGRP only sends incremental updates, rather than full periodic updates. Once the initial routing table is established, only the changes to the routing table are sent to all the routers in the network, reducing network traffic.
  3. Scalability and Efficiency: EIGRP is a highly scalable protocol, able to handle large networks efficiently. Its “Diffusing Update Algorithm” (DUAL) ensures that there are no routing loops and that all routers have a consistent view of the network.


Enhanced Interior Gateway Routing Protocol (EIGRP) is a significant term in technology because it refers to a proprietary advanced distance-vector routing protocol developed by Cisco. Its importance lies in its ability to offer swift, precise, seamless, and scalable routing for any network topology, including LANs, WANs, and other large-scale internetworks. Unlike other routing protocols, EIGRP uses a complex metric to calculate the cost of routes and employs a Diffusing Update Algorithm (DUAL), ensuring network stability and preventing routing loops. It supports various network protocols, offers automatic redistribution, and allows for load balancing across equal or unequal metric cost paths. Hence, EIGRP is critical for maintaining communication efficiency, robustness, and reliability in complex network environments.


The Enhanced Interior Gateway Routing Protocol (EIGRP) is a networking protocol that allows routers to exchange information more efficiently and accurately. The primary purpose of EIGRP is to facilitate routing decisions within a network. It ascertains the best path for data transmission by considering various factors such as bandwidth, delay, reliability, and load. By doing so, it aids in mitigating network congestion and enhances overall data transmission efficiency.Developed by Cisco, EIGRP is widely used in large networks due to its ability to adapt rapidly to network changes and robust fault tolerance. When a network topology changes (for instance, when a new router is added or an existing one fails), EIGRP updates only the routers that are affected by the change, rather than all routers on the network. This makes it more scalable and less resource-intensive compared to older protocols. Furthermore, its support for different types of network topologies and protocols, including IP and IPv6, makes EIGRP a versatile and essential tool in network routing.


1. Telecommunication Networks: Telecom companies who manage broad and complex networks that interconnect multiple systems across vast geographical areas use the Enhanced Interior Gateway Routing Protocol (EIGRP). With its fast convergence, loop prevention mechanism, and smart bandwidth usage, EIGRP is used to ensure secure, reliable, and efficient routing of information across Telecom networks.2. Large Enterprise Networks: Large corporations with global offices use EIGRP to effectively connect multiple LANs and WANs in a large-scale network. For instance, a multinational company may use EIGRP in its internal network to manage hundreds or thousands of routers, ensuring technical efficiency and minimizing network downtime.3. Internet Service Providers: ISPs often use EIGRP to manage diverse and complex networks. It provides advantages in scalability, maximum hop count, and capability to use multiple protocols. This allows ISPs to distribute bandwidth favorably and ensures smooth data communication, ultimately providing consistent and reliable internet services to their customers.

Frequently Asked Questions(FAQ)

Q: What is Enhanced Interior Gateway Routing Protocol (EIGRP)?A: EIGRP is a Cisco proprietary routing protocol that improves the efficiency and scalability of traditional Interior Gateway Routing Protocol (IGRP). Its enhanced features make the routing process faster and more reliable in large and complex networks.Q: How does EIGRP work?A: EIGRP primarily works on a Diffusing Update Algorithm (DUAL). The DUAL ensures that the routers have a consistent view of the network. EIGRP creates and maintains routing tables to store and sort the best paths to each destination network.Q: What are the main features of EIGRP?A: The main features are fast convergence, partial update capability, support for multiple network-layer protocols, and support for Variable-Length Subnet Masking (VLSM) and Classless Inter-Domain Routing (CIDR).Q: Is EIGRP a distance-vector or link-state protocol?A: EIGRP is commonly classified as a hybrid routing protocol, as it combines aspects of both distance-vector and link-state protocols, even though Cisco officially refers to it as an advanced distance-vector protocol.Q: Does EIGRP support load balancing?A: Yes, EIGRP supports equal and unequal cost load balancing which optimizes the network by spreading traffic across multiple paths.Q: What protocols are compatible with EIGRP?A: EIGRP is compatible with protocols such as Internet Protocol (IPv4 and IPv6), AppleTalk, and Novell’s Internetwork Packet Exchange (IPX).Q: Can non-Cisco devices use EIGRP?A: Initially, EIGRP was a Cisco-proprietary protocol, which limited its use only to Cisco devices. However, in the year 2013, Cisco opened the protocol for standardization and now it can be used by non-Cisco devices too.Q: What is a feasible successor in EIGRP?A: A feasible successor is a backup route in EIGRP, which is selected in advance in the event of failure of the primary route. It makes network convergence faster and improves the overall performance.Q: What is the metric in EIGRP?A: In EIGRP the metric is a composite metric which is computed based on bandwidth, delay, reliability, load, and MTU size of the path. This provides flexibility and accuracy in determining the best path for data delivery.

Related Finance Terms

  • Interior Gateway Protocol (IGP)
  • Convergence
  • Routing Information Protocol (RIP)
  • Dual Algorithm
  • Autonomous System (AS)

Sources for More Information


About The Authors

The DevX Technology Glossary is reviewed by technology experts and writers from our community. Terms and definitions continue to go under updates to stay relevant and up-to-date. These experts help us maintain the almost 10,000+ technology terms on DevX. Our reviewers have a strong technical background in software development, engineering, and startup businesses. They are experts with real-world experience working in the tech industry and academia.

See our full expert review panel.

These experts include:


About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

More Technology Terms

Technology Glossary

Table of Contents