Now that you have seen the details of how EIGRP forms neighbor relationships, exchanges routing information, and calculates the best route, the rest of this section looks at the most interesting part of EIGRP: EIGRP’s work to converge to a new loop-free route.
Loop avoidance poses one of the most difficult problems with any dynamic routing protocol. DV protocols overcome this problem with a variety of tools, some of which create a large portion of the minutes-long convergence time after a link failure. LS protocols overcome this problem by having each router keep a full topology of the network, so by running a rather involved mathematical model, a router can avoid any loops.
EIGRP avoids loops by keeping some basic topological ...