The older version of IGRP and RIP advertised it’s entire database of known networks on each update interval expiry. It also served a dual purpose of detecting neighbors, verifying neighbors continuous presence, learning new routes, and refreshing or withdrawing existing learned routes.
EIGRP’s enhancements to these requirements splits these into two functions:
- Hello Protocol
- RTP Protocol
EIGRP uses the Hello protocol for neighbor discovery, and maintains neighbor adjacency ensuring their continued presence on the network.
RTP messages take care of the route exchanging functions between neighbors reliably