IGRP is a proprietary routing protocol designed by Cisco and can only be used in a homogeneous network of Cisco routers. IGRP is a distance-vector protocol that considers delay, bandwidth and other optional parameters to determine the best path.
IGRP uses an autonomous system number parameter in the configuration. All routers with the same autonomous system number will share router advertisements and participate. This number is arbitrary but must be the same on all routers within the autonomous system.
To configure a router to participate in IGRP routing within autonomous system 5 and advertise routing information about the 192.168.200.0 network, use:
router igrp 5