6.2 EIGRP Technology
6.2.1 EIGRP features
EIGRP includes many new technologies, each of which represents an improvement in operating efficiency, rapidity of convergence, or feature/functionality relative to IGRP and other routing protocols. These technologies fall into one of the following four categories:
  • Neighbor discovery and recovery
  • Reliable Transport Protocol
  • DUAL finite-state machine
  • Protocol-specific modules

In addition to these categories of technological improvements, EIGRP was also treated to some other substantial enhancements relative to IGRP. These enhancements may defy easy categorization, but were needed to keep pace with the ongoing evolution of IP as well as other routed protocols. EIGRP enhances the security of a network, for example, by permitting authentication to be used between routers. This function is very similar to the authentication supported by OSPF and can be used in conjunction with any routed protocol. Other innovations such as support for VLSM and CIDR are specific only to IP. As such, they are integrated in a protocol-specific module rather than included in EIGRP itself.