EIGRP
EIGRP (Enhanced Interior Gateway Routing Protocol) is a Cisco-proprietary advanced distance-vector routing protocol used in computer networks for dynamic routing. It combines features of both distance-vector and link-state protocols, offering fast convergence, efficient bandwidth usage, and support for multiple network layer protocols like IPv4 and IPv6. EIGRP uses the Diffusing Update Algorithm (DUAL) to calculate loop-free paths and maintain routing tables.
Developers and network engineers should learn EIGRP when working in Cisco-centric environments, such as enterprise networks or data centers, to enable scalable and reliable routing with minimal configuration overhead. It is particularly useful for scenarios requiring fast network recovery from failures, support for variable-length subnet masking (VLSM), and integration with Cisco devices, making it a key skill for roles involving network design, administration, or troubleshooting.