EIGRP3B.1 # ENHANCED INTERIOR GATWAY ROUTING PROTOCOL STATE AND EXPLAIN
Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector (often called hybrid) interior gateway routing protocol used in computer networks to route IP packets efficiently within an autonomous system (AS), It was originally developed by Cisco. It supports multiple network layer protocols, such as IPv4, IPv6, IPX, and AppleTalk.. EIGRP is a successor to the Interior Gateway Routing Protocol (IGRP). It will establish the neighbore relationship between two routers become neighbors when they see hello packets on a common network. : Neighbor Discovery/Recovery, Reliable Transport Protocol, DUAL Finite State Machine, Protocol Dependent Modules.
Overview of EIGRPType : Interior Gateway Protocol (IGP)
Algorithm : DUAL (Diffusing Update Algorithm)
Administrative Distance : 90 (internal routes) & 170 (external routes)
Protocol Number : 88
Transport : Uses RTP (Reliable Transport Protocol) instead of TCP/UDP
Metric : Composite metric based on bandwidth, delay (by default)
Default metric formula : Metric = (10^7 / minimum bandwidth) + total delay
{Reliability and load are disabled by default}
3B.2 # CORE COMPONENT OF EIGRP AND THEIR FUNCTIONS
- Protocol-dependent modules (PDMs) are used by the routing protocol EIGRP to make decisions about adding routes learned from other sources; for example other routers or routing protocols to the routing table.
- Reliable Transport Protocol (RTP) to ensure that packets are delivered in order and to ensure that routers receive specific packets. A sequence number is included in each EIGRP packet. Its means for sending message.
- Neighbor Discovery/Recovery (NDR) solves a set of problems related to the interaction between nodes attached to the same link.
- Diffusing Update Algorithm (DUAL) is an algorithm used by EIGRP to select and maintain the best route to each remote network. DUAL is also used for the discover a backup route if there is one available.
- It is based on hybrid protocol only cisco router supports eigrp protocol.
- It is the best path from source to destination with respect to hop count as well as bandwidth.
- In its protocol routers sends better packet (2 kb) to the neighboring router in every two seconds.
- It supports classless networks.
- In its routing protocol router generate following three tables.
i) Topology table (All round): Lists directly connected EIGRP neighbors. Maintained using Hello packets.
ii) Routing table (Best path): Stores all learned routes from neighbors. Tracks successors and feasible successors.
iii) Neighboring table (Near path) : Contains best routes selected by DUAL. Installed routes are used for packet forwarding. - Topology table contains these entries all the protocol route of network from source to destination.
- Maximum hop count is 255 with default is 100.
- It also uses the autonomous system suitable for small to large network.
- Administrative distance is 90.
- Feasible distance (FD) is the best metric along a path to a destination network, including the metric to the neighbor advertising that path.
- Reporting distance (RD) is the total metric along a path to a destination network as advertised by an upstream neighbor.
- Feasibility successor (FS) A destination is moved from the topology table to the routing table when there is a feasible successor. A feasible successor is a path whose reported distance is less than the feasible distance and it is considered a backup route.
- Feasibility condition is states that a route will not be accepted if the Reported Distance is more than the best path’s Feasible Distance.
- EIGRP successor is the neighbor that has meet the Feasible Distance and has the least cost path towards the destination.
- Query process EIGRP is advanced distance vector. It relies on its neighbors to provide routing information. Queries are sent out when a route is lost and no feasible successor is available, the EIGRP need to converge fast
Properties :
Terms and conditions of EIGRP protocol
EIGRP Packet Types
1. Hello – Neighbor discovery and maintenance.
2. Update – Route information.
3. Query – Requests route information.
4. Reply – Responses to queries.
5. Acknowledgment – Confirms reliable delivery.
3B.3 # ENHANCED INTERIOR GATWAY ROUTING PROTOCOL CONFIGURATION
Diagram:-
| Port | Status | Device |
|---|---|---|
| Router | ||
| Serial 0/0 | Routed link-port | Side_A |
| Serial 0/0 | Routed link-port | Side_B |
| Serial 0/1 | Routed link-port | Side_B |
| Serial 0/0 | Routed link-port | Side_C |
| Switch_Layer 2 | ||
| FastEthernet 0/1 | Trunk port | Switch0 |
| FastEthernet 0/1 | Trunk port | Switch1 |
| FastEthernet 0/1 | Trunk port | Switch2 |
| Broadcast & Collision domain | ||
| Number of broadcast domain | Number of collision domain | |
| 5 | 11 |
# EIGRP Configuration Lab : -
1) Configuration of Side_A
Router >enable
Router #configure terminal
Router (config) #no ip domain lookup
!
Router (config)#hostname Side_A
!
Side_A (config)#enable secret Cisco!123
!
Side_A (config)#line vty 0 4
Side_A (config-line)#password Cisco@123
Side_A (config-line)#login
Side_A (config-line)#exec-timeout 5 0
Side_A (config-line)#exit
!
Side_A (config)#line vty 0 4
Side_A (config-line)#transport input ssh
Side_A (config-line #end
Side_A (config) #username senior
Side_A (config-if #ip domain-name ssm.in
Side_A (config-if #crypto key generate rsa
Side_A (config-if #ip ssh version 1/2
Side_A (config-if #ip ssh timeout 90 authentication-retries 2
Side_A (config-if #exit
!
Side_A (config)#interface FastEthernet0/0
Side_A (config-if)#ip address 192.168.1.1 255.255.255.0
Side_A (config-if)#no shutdown
Side_A (config-if)#exit
!
Side_A (config)#interface Serial0/0
Side_A (config-if)#ip address 10.10.10.1 255.0.0.0
Side_A (config-if)#encapsulation hdlc
Side_A (config-if)#clock rate 64000
Side_A (config-if)#no shutdown
Side_A (config-if)#exit
!
Side_A (config)# router eigrp 760
Side_A (config-router)# network 10.0.0.0 0.0.0.255
Side_A (config-router)# network 192.168.1.0 0.0.0.255
Side_A (config-router)#no auto summary
Side_A (config-router# exit
!
2) Configuration of Side_B
Router >enable
Router #configure terminal
Router (config) #no ip domain lookup
!
Router (config)#hostname Side_B
!
Side_B (config)#enable secret Cisco!123
!
Side_B (config)#line vty 0 4
Side_ B (config-line)#password Cisco@123
Side_ B (config-line)#login
Side_ B (config-line)#exec-timeout 5 0
Side_ B (config-line)#exit
!
Side_ B (config)#line vty 0 4
Side_ B (config-line)#transport input ssh
Side_ B (config-line #end
Side_ B (config) #username senior
Side_ B (config-if #ip domain-name ssm.in
Side_ B (config-if #crypto key generate rsa
Side_ B (config-if #ip ssh version 1/2
Side_ B (config-if #ip ssh timeout 90 authentication-retries 2
Side_ B (config-if #exit
!
Side_ B (config)#interface FastEthernet0/0
Side_ B (config-if)#ip address 192.168.2.1 255.255.255.0
Side_ B (config-if)#no shutdown
Side_ B (config-if)#exit
!
Side_ B (config)#interface Serial0/0
Side_ B (config-if)#ip address 10.10.1.2 255.0.0.0
Side_ B (config-if)#no shutdown
Side_ B (config-if)#exit
!
Side_ B (config)#interface Serial0/0
Side_ B (config-if)#ip address 20.20.2.1 255.0.0.0
Side_ B (config-if)#encapsulation hdlc
Side_ B (config-if)#clock rate 64000
Side_ B (config-if)#no shutdown
Side_ B (config-if)#exit
!
Side_ B (config)# router eigrp 760
Side_ B (config-router)# network 10.0.0.0 0.0.0.255
Side_ B (config-router)# network 20.0.0.0 0.0.0.255
Side_ B (config-router)# network 192.168.2.0 0.0.0.255
Side_ B (config-router)#no auto summary
Side_ B (config-router# exit
!
3) Configuration of Side_C
Router >enable
Router #configure terminal
Router (config) #no ip domain lookup
!
Router (config)#hostname Side_C
!
Side_C (config)#enable secret Cisco!123
!
Side_C (config)#line vty 0 4
Side_C (config-line)#password Cisco@123
Side_C (config-line)#login
Side_C (config-line)#exec-timeout 5 0
Side_C (config-line)#exit
!
Side_C (config)#line vty 0 4
Side_C (config-line)#transport input ssh
Side_C (config-line #end
Side_C (config) #username senior
Side_C (config-if #ip domain-name ssm.in
Side_C (config-if #crypto key generate rsa
Side_C (config-if #ip ssh version 1/2
Side_C (config-if #ip ssh timeout 90 authentication-retries 2
Side_C (config-if #exit
!
Side_C (config)#interface FastEthernet0/0
Side_C (config-if)#ip address 192.168.3.1 255.255.255.0
Side_C (config-if)#no shutdown
Side_C (config-if)#exit
!
Side_C (config)#interface Serial0/0
Side_C (config-if)#ip address 20.20.2.2 255.0.0.0
Side_C (config-if)#encapsulation hdlc
Side_C (config-if)#clock rate 64000
Side_C (config-if)#no shutdown
Side_C (config-if)#exit
!
Side_C (config)# router eigrp 760
Side_C (config-router)# network 20.0.0.0 0.0.0.255
Side_C (config-router)# network 192.168.3.0 0.0.0.255
Side_C (config-router)#no auto summary
Side_C (config-router# exit
!
3B.4 # EIGRP TROUBLESHOOTING
Router (config) #show ip eigrp neighbors
Router (config) #show ip route
Router (config) #show ip protocols
Router (config) #show ip eigrp neighbors detail
Router (config) #show ip eigrp traffic
Router (config) #show protocols.
Router (config) #debug eigrp packets
Router (config) #debug eigrp packets terse
