EIGRP 101 documentation

EIGRP = enchanced version of igrp.

- hybrid protocol

^ initial exchange of full routing table between eigrp neighbors.
^ after that initial exchange of full tables, an eigrp router will send an update only when there is a change in network. That update will reflect only those changes and will not contain every eigrp route known to sender. ( not every 30s like rip / distance vector )

++ from rip
rapid convergence.
^ backup routes / feasible successors are calculated before they are actually needed due to the loss of primary route ("successors").

+ consider bandwidth and delay when calculating routes. rather than primitive " hop count " of RIP.

+ NO Longer cisco- prop. Multivendor environtment.

eigrp use hello packet ( multicast to 224.0.0.10 ) to establish and maintain neighbor relationship.

- RTP -> used to handle transport of messages between eigrp-enabled routers.
- eigrp with different as number cant become neighbor!
- eigrp authentication must have same password!
- router must be on same subnet
- k-values must match



adjacencies -- its kept alive by steady flow of hello packets from the neighbor.
if those hellos stop coming, the adjacency is eventually dropped.

======================


3 table utama:

- route table ( best route to each remote network ).
- topology table ( keeps all known valid, loop-free routes to same network ).
- neighbor table  ( information eigrp neighbor )



#show ip route eigrp




  ------r2-----
r1 r4
  ------r3-----


r2 : successor / next hop ( best path )    ++ metric
r3 : feasible successor / ( valid path / no loop )   



r2 masuk di eigrp routing table   !!   -> routing utama = successor
r2+r3 masuk di topology table     !! 

^ neighbor table ga ada hubungannya ( isinya cm router yg jadi tetangga eigrpnya )



feasible succesor = backup succesor.
klo link sucessor putus feasible akan menggantikan menjadi succesor sementara hingga link up lagi.
===================
EIGRP AS 100

R1
R2      ---|---            R3
  frame relay cloud



^ hub and spoke topology


R1
#conf t
#router eigrp 100                  !! 100 = AS number
#network 172.12.123.0 0.0.0.255                 !! network  [network adv by eigrp] [wild card bit]


R2
#conf t
#router eigrp 100                  !! 100 = AS number
#network 172.12.123.0 0.0.0.255                 !! network  [network adv by eigrp] [wild card bit]


R3
#conf t
#router eigrp 100                  !! 100 = AS number
#network 172.12.123.0 0.0.0.255                 !! network  [network adv by eigrp] [wild card bit]



!! verifikasi !!

R1
# show ip eigrp neigh interface uptime
172.12.123.3 se1/0 00:00:05 ->>  muncul tetangganya
172.12.123.2 se1/0 00:00:23


# show ip route eigrp    !! masih kosong


!! ^ info paling penting ip address sama uptimenya !!


!! di eigrp bisa ga pake wild card bit. ga kayak ospf !!
!! tp nanti di add sbg classfull address !!
#network 172.12.123.0


^ !! class B network / 255.255.0.0 !!