3.5.d [i] General operations
ENHANCED INTERIOR GATEWAY ROUTING PROTOCOL
Through the years Cisco’s proprietary (as of this writing) EIGRP has been referred to as a hybrid routing protocol and as an advanced distance vector routing protocol. Arguments can be made in favor of either, however, the fact is EIGRP exhibits behaviors of both link state and distance vector routing protocols no matter the manner to which it is referred.
It’s advantages include:
Rapid convergence because of the Diffusing Update Algorithm
Low CPU overhead
Manual or automatic route summarization
EIGRP employs protocol 88 (http://www.ietf.org/rfc/rfc1700.txt) and uses the multicast address of 126.96.36.199 for hellos and updates (http://www.iana.org/assignments/multicast-addresses/multicast-addresses.xml).