What is one of the key advantages of using EIGRP over other routing protocols?
A) EIGRP uses a link-state algorithm to determine the best path.
B) EIGRP supports unequal-cost load balancing, which allows for more efficient use of network resources.
C) EIGRP is an open standard, widely supported across different vendor devices.
D) EIGRP does not require a hierarchical network design and can function without a clear network topology.
Option A: EIGRP uses a link-state algorithm to determine the best path.
This option is incorrect because EIGRP does not use a link-state algorithm. Instead, EIGRP is a hybrid routing protocol that combines characteristics of both distance-vector and link-state protocols. It primarily uses an advanced distance-vector algorithm known as the Diffusing Update Algorithm (DUAL) to calculate the best path to a destination.
Link-state protocols, such as OSPF (Open Shortest Path First), require routers to have a full view of the network topology, meaning they know the exact state of every link in the network. EIGRP, however, relies on information about its directly connected neighbors and the distance to each destination, making it less resource-intensive than link-state protocols. The DUAL algorithm allows EIGRP to quickly converge and provides loop-free paths, which is why EIGRP is often preferred for its fast convergence times and efficiency in certain network environments.
Option B: EIGRP supports unequal-cost load balancing, which allows for more efficient use of network resources.
This option is correct and highlights one of the key advantages of EIGRP. Unlike many other routing protocols, EIGRP supports unequal-cost load balancing. This means that EIGRP can use multiple paths to a destination that have different metrics or costs, allowing the protocol to distribute traffic more efficiently across available routes.
For example, if there are two routes to a destination, one with a slightly higher metric than the other, EIGRP can still use both paths to balance the traffic load. This capability helps in optimizing the use of network bandwidth and improving overall performance. In contrast, protocols like OSPF or RIP (Routing Information Protocol) typically only support equal-cost load balancing, where all paths must have the same metric to be used for load balancing.
Unequal-cost load balancing is particularly beneficial in networks with diverse link types, such as a mix of high-speed and lower-speed links. By enabling traffic to be spread across these links in proportion to their capacities, EIGRP helps to prevent any single link from becoming a bottleneck, thus enhancing network efficiency and reliability.
Option C: EIGRP is an open standard, widely supported across different vendor devices.
This option is incorrect because EIGRP was originally a proprietary protocol developed by Cisco. For many years, EIGRP was only available on Cisco devices, making it less interoperable with equipment from other vendors. While Cisco has since released EIGRP as an informational RFC (Request for Comments) under RFC 7868, it is still not as widely supported across different vendor devices as open standard protocols like OSPF or BGP (Border Gateway Protocol).
The proprietary nature of EIGRP historically limited its adoption in multi-vendor environments, where organizations often prefer open standard protocols to ensure compatibility and flexibility. While EIGRP’s capabilities, such as fast convergence and support for unequal-cost load balancing, make it a powerful protocol within Cisco environments, its use in non-Cisco networks remains limited compared to open standards.
Option D: EIGRP does not require a hierarchical network design and can function without a clear network topology.
This option is incorrect and somewhat misleading. While EIGRP does not strictly require a hierarchical design like OSPF, where areas are structured in a hierarchy to improve scalability and reduce routing overhead, it still benefits from a well-structured network topology. In fact, a clear and organized network design can enhance EIGRP’s performance and efficiency.
EIGRP operates efficiently in both flat and hierarchical network designs, but a well-planned topology can help minimize the number of EIGRP neighbors and reduce the overall complexity of the network. In large networks, hierarchical designs can also help limit the scope of routing updates and reduce the size of routing tables, even when using EIGRP.
Moreover, while EIGRP can function in a less structured environment, it still requires a logical topology that defines the relationships between routers and how they communicate. Without a clear network design, managing and troubleshooting an EIGRP-enabled network can become challenging, leading to potential inefficiencies and increased administrative overhead.
Summary
EIGRP is a robust routing protocol with several unique features that differentiate it from other protocols. Understanding these features is crucial for network administrators when choosing the right protocol for their network environment.
- Option A: EIGRP uses a link-state algorithm to determine the best path is incorrect because EIGRP uses the Diffusing Update Algorithm (DUAL), a distance-vector algorithm.
- Option B: EIGRP supports unequal-cost load balancing, which allows for more efficient use of network resources is correct, highlighting one of EIGRP’s key strengths.
- Option C: EIGRP is an open standard, widely supported across different vendor devices is incorrect, as EIGRP was originally a Cisco proprietary protocol, and its adoption outside of Cisco environments is still limited.
- Option D: EIGRP does not require a hierarchical network design and can function without a clear network topology is incorrect and misleading because, while EIGRP can operate in non-hierarchical networks, a well-structured topology is still beneficial.
By understanding these options, network administrators can better appreciate the strengths and limitations of EIGRP and make informed decisions about its implementation in their networks.