IGRP
Interior Gateway Routing Protocol (IGRP) was developed as a replacement for RIP.
IGRP is a distance vector routing protocol like RIP, but it has several features that make it better than RIP.
IGRP devices send network broadcasts every 90 seconds by default.
When a topology change occurs, IGRP updates other devices immediately. This called a flash or triggered update.
IGRP considers bandwidth, delay, link reliability, and the load of the network link when choosing the best path.