|  | 11.8 | Interior Gateway Protocol (IGP) and Exterior Gateway Protocol (EGP)
| 11.8.4 | IGRP and EIGRP

IGRP and EIGRP are routing protocols that were developed by Cisco Systems, Inc., therefore, they are considered proprietary routing protocols. IGRP was developed specifically to address problems associated with routing in large multi-vendor networks that were beyond the scope of protocols such as RIP. Like RIP, IGRP is a distance-vector protocol; however, when determining the best path, it also takes into consideration such things as bandwidth, load, delay, and reliability. Network administrators can determine the importance given to any one of these metrics, or, allow IGRP to automatically calculate the optimal path.

EIGRP is an advanced version of IGRP. Specifically, EIGRP provides superior operating efficiency and combines the advantages of link-state protocols with those of distance-vector protocols.