Enhanced Interior Gateway Routing Protocol. EIGRP requires much less processing time, memory and design effort than OSPF. However, EIGRP is Cisco-proprietary, so if an internetwork uses some non-Cisco routers, EIGRP cannot be used on those routers.

EIGRP does not fit neatly into the general categories of distance vector and link-state routing protocols. Sometimes Cisco refers to EIGRP as an advanced distance vector protocol, or a new type: a balanced hybrid routing protocol.

It includes the following topics -

• EIGRP Operation and neighbors
• Exchanging EIGRP topology information
• Best Route Calculation feasible distance and reported distance
• EIGRP Convergence metrics successors and feasible successors
• The Query and Reply Process
• EIGRP Summary and Comparisons with OSPF
• EIGRP configuration verification and authentication
• EIGRP Maximum Paths and Variance
• Tuning the EIGRP Metric Calculation