How EIGRP protocol will work, Enhanced Interior Gateway Routing Protocol explanation,
It stands for Enhanced Interior Gateway Routing Protocol.
It is an open standard routing protocol. (Earlier it was a cisco proprietary but after a
time gap (2013) Cisco declared it as an open standard protocol)
It is a layer 3 protocol.
It's protocol number is 88.
It has a hybrid routing protocol because it has feature of both distance vector and link
state routing protocol.
It is also known as an advanced distance vector routing protocol.
It is an IGP (Interior gateway protocol) type protocol.
It is a classless routing protocol.
It sends triggered updates (it means EIGRP routers does not send periodic, full
routing table information,
EIGRP will send the update only when change will occur in the topology). EIGRP
uses diffusing Update Algorithm (DUAL) to determine the best path in the topology.
In EIGRP if two routers are configured with same AS number then neighborship will
be formed between them.
EIGRP traffic will either sent as unicast or as multicast on address 224.0.0.10.
It is a reliable protocol because it provides the acknowledgement of updates (just like
TCP).
It uses Reliable transport protocol (RTP) to ensure the delivery and acknowledge of
EIGRP packets. Maximum hop count value is 255 in EIGRP protocol.
It uses RTP protocol to get the reliability of updates in EIGRP protocol. (but hello
messages will not be reliable through RTP)
It uses some timers HELLO-05 seconds (R1(config-if)#ip hello-interval eigrp 106)
• HOLD-15 seconds (R1(config-if)#ip hold-time eigrp 10 17)
It A.D value is 90-Internal routes
170-External routes
It supports both equal and unequal cost load balancing in EIGRP