eigrp dual
What Is DUAL? EIGRP’s Diffusing Update Algorithm
The Diffusing Update Algorithm (DUAL) is the algorithm EIGRP uses to guarantee loop-free routes and maintain backup paths throughout the routing domain, recalculating a route whenever a change could otherwise introduce a loop. This guide covers what DUAL actually does, corrects a common point of confusion about how EIGRP really prevents loops, and walks through...
Introduction to EIGRP
Enhanced Interior Gateway Routing Protocol (EIGRP) was introduced by Cisco in 1992 as an advanced distance-vector routing protocol, originally running only on Cisco devices. It remained Cisco-proprietary for over two decades before becoming an open, multi-vendor standard — a milestone worth getting the date right on, since it’s commonly misstated. From Proprietary Protocol to Open...