Advanced Networking Administrator Test Prep

Answer: C - Routers using IGRP send routing updates every 90 seconds.

Key Takeaway: IGRP is a distance-vector routing protocol that uses bandwidth and delay as parameters instead of hop count. It has a maximum hop limit of 100 and can be configured to support a network diameter of 255. IGRP sends routing updates to its neighbors every 90 seconds. This update period of 90 seconds is beneficial compared to a 30 second period for RIP.