2. Routing protocols
Routing protocols are the set of rules used by the routers to
communicate between source & destination. they do not
move the information to source to destination only update the
routing table(contains the information
Each protocol has its own algorithm to choose the best path.
The metrics by routing protocols ,
*Number of network layer devices along with the path (hop
count)
*Bandwidth
*Delay
*Load
*MTU
*Cost
Routing protocols store the result of these metrics in routing
table.
3. TYPES OF ROUTING PROTOCOL
DYNAMIC
STATIC ROUTING
ROUTING
PROTOCOL
PROTOCOLS
DISTANCE
LINK STATE
VECTOR
RIP IGRP EIGRP
RIPv1 OSPF
RIPv2
4. Static routing protocols
Static routing ,when an administrator manually assigns the path
from source to destination network. It provides more security to
network. The main drawback of static routing is that when a link
fail in the internetwork all the network goes down. This is feasible
in small networks, but not in large networks.
Advantages
No overhead on router CPU.
No bandwidth usage between links.
Security (only administrator add routes.)
Disadvantages
Administrator must really understand internetwork & how each
router is connected.
Not practical on large networks as it is time intensive.
Administrator must update all routers.
5. Dynamic routing protocols
Dynamic routing is the process in which routing tables are
automatically updates by routing table
*Dynamically discover & maintains routes.
*Calculate routes
*Distributing routing updates to other routers in the network
Advantages
-less work in maintaining the configuration when adding & deleting
networks.
-protocols automatically react to the topology changes.
-configuration is less-prone.
-More scalable.
Disadvantages
-Routers resource are used.
-More administrator knowledge is required for configuration
6. Types of dynamic routing
protocols
The dynamic routing protocols can be categorized on the basis of
various parameters .Dynamic routing protocols are classified into
two protocols:
1. Distance Vector Routing Protocols: - It uses simple algorithms
that calculate cumulative distance value between routers based on
hop count.
Example:
Routing Information Protocol(RIP)
Interior Gateway Routing Protocols (IGRP
2. Link State Routing Protocols: - It uses sophisticated algorithms
that maintain a complex database of internetwork topology.
Example:
Enhanced Interior Gateway Routing Protocol(EIGRP)
Open Shortest Path First (OSPF)
7. Routing Information
Protocol (RIP)
RIP allows routers to exchange their routing tables at a predefined
interval
RIP is a distance-vector routing protocol which employs the hop
count as a routing metric.
RIP router transmitted full updates in every 30 seconds.
Characteristics of RIP include:
Uses hop count metric
Supports 15 hop-count limit
Supports six equal-cost paths
AD value is 120.
Broadcasting done in RIP & RIPv1.
Supports classful networks.
8. RIPv2
It is a distance vector protocol.
AD value is 120.
Metric is hop count.
Supports classless network.
Supports VLSM/CIDR.
Maximum hop count is 15.
Route updates after 30 sec.
Uses multicast ip for convergence.
It supports authentication.
9. Configuring RIP
se 0/1/0 192.168.2.0
192.168.2.1
se 0/1/0
192.168.2.2
fa 0/0 fa 0/0
192.168.1.0 192.168.3.0
192.168.3.2 192.168.3.3
192.168.1.2 192.168.1.3
10. Configure RIP
Configuration for RIPv1
Router>enable
Router# configure terminal
Router(config)#router rip
Router(config)#serial 0/1/0
Router(config-router)#network _network address of own router(e.g.192.168.1.0)
Router(config-router)#version 1
Router(config)save & exit
Configuration for RIPv2
Router>enable
Router# configure terminal
Router(config)#router rip
Router(config)#serial 0/1/0
Router(config-router)#network _network address of own router(e.g.192.168.1.0)
Router(config-router)#version 2
Router(config)save & exit
11. INTERIOR GATEWAY ROUTING
PROTOCOL (IGRP)
IGRP is a distance vector protocol. To overcome RIP limitations
IGRP introduced. The metrics used are bandwidth, load, delay,
MTU AND reliability. Routing updates are broadcast every 90
seconds (by default).It is used by routers to exchange routing data
within an autonomous system.
The following are the characteristics of IGRP:
- Uses composite metrics
- Uses multipath routing
- Supports unequal-cost load balancing
- Supports hold-downs
- Supprts spilt horizons
12. Configuring IGRP
se 0/1/1
se 0/1/0 20.0.0.0
10.0.0.0 20.0.0.1
10.0.0.1 se 0/1/0
se 0/1/0
10.0.0.2 20.0.0.2
fa 0/0
fa 0/0 fa 0/0
192.168.3.0
192.168.1.0 192.168.2.0
192.168.1.2 192.168.1.3 192.168.2.2 192.168.2.3 192.168.3.2 192.168.3.3
13. Configure igRP
The syntax for configuring IGRP is :
-Router igrp AS_number (1 to 65535)
-Network IP_networks
Configure IGRP,
Router>enable
Router#configure terminal
Router#(config)#router igrp 100 (AS Number)
Router#(config-router)# network _ network address of own router
Router#(config-router)#exit
Router#(config)#
Verifying IGRP configurations,
Show ip route (I indicates that IGRP was added as the routing protocol.)
Show ip protocols
Show ip igrp events
14. Enhanced INTERIOR GATEWAY
ROUTING PROTOCOL (eIGRP)
Works on any condition. It’s supports the features both distance
vector & link state protocol. It is a cisco proprietary protocol. EIGRP
is an ideal protocol in the large networks. The AD value of EIGRP is
90. By default, bandwidth & delay are the activated metrics. EIGRP
uses the following tables for route discovery i.e. Neighbor Table,
Topology Table, Route Table.
The following are the characteristics of EIGRP:
- communication done via RTP (capable of transmitting both multicast & unicast )
- uses DUAL algorithm
- supports classless network
- supports VLSM/CIDR,
- supports Discontiguous network.
- supports all layer 3 protocols (IPv4, IPX, and IPv6)
15. Configuring EIGRP
R1 se 0/1/0 R2
192.168.2.1 192.168.2.0/30
se 0/1/0
192.168.2.2
fa 0/0 fa 0/0
192.168.1.0/25 192.168.1.128/25
192.168.1.2 192.168.1.3 192.168.1.129 192.168.1.130
16. Configure EIGRP
R1>enable
R1#configure terminal
R1#(config)#router eigrp 100(AS Number)
R1#(config-router)#network _ network address of own router
R1#(config-router)#exit
R1#(config)#
Verifying EIGRP configurations,
Show ip route (D indicates that EIGRP was added as the routing
protocol.)
Show ip eigerp neighbors
Show ip eigrp topology
17. OPEN SHORTEST PATH FIRST
(OSPF)
The large network can be broken into the small areas so the router in
one area know less topology and they don’t have information about
other areas routers. Creating OSPF areas result in smaller database
which reduce the memory consumption and processing.
OSPF maintains a two layer hierarchy consisting of:
-Backbone area (area 0)
-Off backbone area (areas1-65,535)
The following are the characteristics of OSPF:
-AD value is 110.
-supports classless network
-supports VLSM/CIDR & has unlimited hop counts
-Supports hierarchical network.
-Route propagation using multicasting.
18. Configuring OSPF
R1 R2
15.15.15.0/8
fa 0/0
172.16.0.0/16
fa 0/0
192.168.1.0/24
AREA 0
19. Configuring OSPF
The syntax for configuring OSPF is :
-process ID
-Network IP_networks
-Wildcard mask
-area
configuration
R1#configure terminal
R1#(config)#router ospf 1
R2#(config-router)#network _ network address of own router_wild card mask_area
e.g. (R2#(config-router)#network _192.168.1.0_0.0.0.255_area 0)
R1#(config-router)#exit
R1#(config)#
Verifying OSPF configurations,
-Show ip route(O indicates that OSPF was added as the routing protocol.)
-Show ip ospf database
-Show ip ospf interface
20. . Routing Protocols Comparison
Name Class Type Administ Metric Classful/ Algorith Transport
rative less m Type
Distance
RIP v1 Distance IGP 120 Hop Count Classful Bellman- UDP/520
Vector Ford
RIP v2 Distance IGP 120 Hop Count Classless Bellman- UDP/520
Vector Ford
OSPF Link State IGP 110 Cost Classless Dijkstra (SP OSPF
F) Protocol 89
IGRP Distance IGP 100 Composite Classful Dijkstra (SP IP Protocol
Vector (BW + DLY) F) 9
Hybrid
EIGRP (Advanced IGP 90 Composite Classless DUAL EIGRP
Distance (internal) (BW + DLY) Protocol 88
Vector) 170
(external)