EIGRP

EIGRP (Enhanced Interior Gateway Routing Protocol)
   
       It is a Advance Distance routing protocol.
       EIGRP is replaced IGRP
       EIGRP use RTP (Reliable Transport Protocol).
       Support for IP and IPv6 Via Protocol dependent modules.
       It is a classless protocol like RIPv2 and OSPF
       It support VLSM and CIDR.
       It is Also Support Summaries networks.
       Best path selection via DUAL.

      It use Bounded And Partial Updates
          Information send only to router that need it.
          It does not sent whole routing table like RIP does.

      DUAL(Diffusing Update Algorithm)
         Guarantee Loop free route.
         It will install back up routes.
         No hold down time because it is loop free.
 
EIGRP use series of tables to store important information about its environments.
   

•         Neighbor table
•         Topology table 
•          Routing table 

   
EIGRP Metrice
      EIGRP use four factor to compare routes and select the best possible path.

•                Bandwidth
•                Delay
•                Reliability
•                Load

       EIGRP uses only bandwidth and delay of the line to determine the best path to a remote network by default.

   Maximum paths and Hop count 
      By default EIGRP can provide equal cost load balancing up to 4 links and you can also load balance across up to 16 links by using the command Router(Config-Router)#maximum-paths ?
    It has default maximum hop count is 100 , but it can be set up to 255.

Example of EIGRP Routing protocol

R0:
- should run EIGRP,
- should use a manual EIGRP summary route
for its 192.168.x.x networks
- should have EIGRP passive interfaces
where appropriate,
- should use no auto-summary to avoid the

presence of "null 0" routes

R1:
- should run EIGRP,
- should have a default route to the ISP router,
- should distribute that default static route to R0,
- should not advertise the 209.12.12.32/30 network with EIGRP,
- should have EIGRP passive interfaces where appropriate,
- should use no auto-summary to avoid the presence of "null 0" routes

ISP:
- does not participate in EIGRP
- uses static routes:
- a summary route to reach
ip route 192.168.0.0 255.255.240.0 se0/0/1
the 192.168.x.x networks
- a static route to the 172.16.5.0/30 network
ip route 172.16.5.0 255.255.255.252 se0/0/1

Summury route
     Summary route is a aggregation of all network.
     in this senario i select the bit from right to left and select the 0 bit after the 1's
128 - 64 - - 32 - - 16 - - 8 - - 4- - 2- - 1

11000000.10101000.00000001.00000000
11000000.10101000.00000010.00000000

11000000.10101000.00000011.00000000
 192 . 168.0.0/22

PC0 - PC3:

- all pc hosts need to have the tenth (.10) ip address in their networks,

- all pc hosts need to have the correct subnet mask and gateway

First step is to configure all PC IP addresses.

Second step is to configure the hostname on the routers. Enter into the router and type the command enable to move into privilege EXEC mode, then type configure terminal to move into global configuration mode and type hostname then the name of the router.

1.     Router>enable
2.     Router#configure terminal
3.     Router(config)#hostname R1

  The next thing you need to do is to configure the interfaces on R0, R1, ISP

Router CLI Commands:

Router>enable

Router#configure terminal

Router(config)#

Router(config)#hostname <router name>

Router(config)#enable secret <secret-password> 

Router(config)#banner motd <$banner message$> 

Router(config)#line console 0

Router(config-line)#password <password> 

Router(config-line)#login

Router(config-line)#exit

Router(config)#line vty 0 4

Router(config-line)#password <password> 

Router(config-line)#login

Router(config-line)#exit

Router(config)#interface <interface type> <interface number>

Router(config-if)#ip address <ip address> <subnet mask>

Router(config-if)#no shutdown

//some of the interfaces will also need:

Router(config-if)#clock rate <rate> 

Router(config-if)#bandwidth <speed> 

Router(config-if)#ip summary-address eigrp <process ID#> <ip address> <subnet mask> 

Router(config)#router eigrp <process ID#> 

Router(config-router)#network <network address> <wildcard mask>

Router(config-router)#network <network address> <wildcard mask>

Router(config-router)#network <network address> <wildcard mask>

Router(config-router)#no auto-summary

Router(config-router)#passive-interface <interface>

Router(config-router)#redistribute static

Verifying Your Configurations

• Show ip route 
• Show ip route eigrp
• Show ip eigrp neighbors
• show ip eigrp topology