2. The full meaning of EIGRP is Enhanced Interior Gateway
Routing Protocol. EIGRP is an advanced distance-vector routing
protocol that is used on a computer network for automating
routing decisions and configuration.
The protocol was designed by Cisco Systems as a exclusive
protocol, available only on Cisco routers.
EIGRP
3. Basic components of EIGRP
1.Neighbor Discovery/ Recovery: The process that routers use to
dynamically learn of other routers on their directly attached networks.
2.Reliable Transport Protocol: The reliable transport is responsible for
guaranteed, ordered delivery of EIGRP packets to all neighbors.
3.DUAL Finite State Machine: Process for all route calculations. It tracks
all routes advertised by all neighbors.
4.Protocol Dependent Modules: The protocol-dependent modules are
responsible for network layer, protocol-specific requirements.
4. Packet types of EIGRP
• Hello/Acks: Hellos are multicast for neighbor discovery/recovery.
They do not require acknowledgment
• Updates: Updates are used to carry reachability of destinations.
• Queries: Queries are always multicast unless they are sent in
response to a received query.
• Replies: Replies are always sent in response to queries to indicate to
the originator.
• Requests: Request packets are used to get specific information from
one or more neighbors.
