CCNA part 5 routing

1. Routing

2. • IP Routing:-
IP Routing is the process of moving packets from
one network to another network using routers.
• Routing Protocols:-
A routing protocol is used by routers to dynamically
find all the n/w in the internetwork and to ensure that
all router have same routing table.
Routing protocol determines the path of packet
through an internetwork. E.g.
RIP,IGRP,OSPF,EIGRP.
• Routed Protocols:-
Routed protocol can be used to send user data
(packet) through the established enterprise.
Routed protocols are assigned to an interface and
determine the method of packet delivery. E.g.IP, IPX.
Apple talk.

3. Types of Routing:-
• Static Routing
• Default Routing
• Dynamic Routing

4. Static Routing
• It is manually configured by administrator.
• Mandatory need of destination network ip.
• It is very secure and fast.
• There is no bandwidth usage between routers.
• Used for small organization with network of 10-15
routers
• Administrative distance for static route is 0 & 1.
[Admin. Distance is ‘trustworthiness’ of routing
information.lesser the AD higher the performance. 0-
very good , 255-very bad]
Disadvantages :-
Used for small network.
Everything to manually
Network change effect complete n/W

5. Configuration of Static Routing
Router#config t
Router(config)#ip routing
Router(config)# ip route <destination_network>
<subnetmask> <IP_address_of_next_hop>
E.G.
• Router(config)#ip route 192.168.2.0
255.255.255.0 10.0.0.2
• Router(config)#exit
• Router#show ip route

6. Default Routing
• When we don’t know the destination ip address then
we can use default routing.
• In internet we use default routing.
Configuration of default Routing:-
Router#config t
Router(config)#ip routing
Router(config)# ip route 0.0.0.0 0.0.0.0 <ip of next hop>
Router(config)# ip route 0.0.0.0 0.0.0.0 10.0.0.2
Router#show ip route

7. Dynamic
Routing

8. Advantage of Dynamic Routing:-
• There is no need to know the destination network.
• Need to advertise only directly connected networks.
• Update the topology which change dynamically.
• Administrative work is reduced.
• Used for large organization.
• Protocols:-
1. Distance vector protocol
2. Link state protocol
3. Hybrid protocol

9. Distance vector protocol:-
• Works with bellman ford algorithm.
• Periodic updates.
• It is classfull routing protocol.
• Full routing table are exchanged.
• Updates are through broadcast.
• Also known by as “Routing by Rumor”.
• E.g. RIP, IGRP.

10. Link state protocol:-
• It works with Dijkstra algorithm.
• It is a classless routing protocol.
• Only missing route are exchanged.
• Updates are through multicast.
• Also known as “Routing by Intelligence”.
• E.G. OSPF, IS-IS

11. Hybrid protocol:-
• It works with DUAL algorithm.
• It is a classless routing protocol.
• Only missing route are exchanged.
• Updates are through multicast.
• Very fast convergence.
• Also known as “Routing by Intelligence”.
• E.G. EIGRP

12. Timers:-
• Update Timer:-
Sets the interval between periodic routing
updates .
• Invalid Timer:-
1.routers wait to hear update .
2.after that period update will send out to all its
neighbors that route is invalid or unreachable.
• Holddown Timer:-
Time for which the information about poorer
route is ignored.
• Flush timer:-
After this timers expires route will remove from
the routing table.

13. RIP (Routing information protocol)
• Open standard protocol.
• It is classfull routing protocol.
• Updates are broadcasted via 255.255.255.255
• Administrative distance is 120.
• Metric is hop count
• Maximum hop counts = 15
• Maximum routers can connect=16.
• Used for small organization.
• Timers(in second)
update timer=30 , invalid timer=180
Holdown timer=180, flush timer=240

14. RIP Versions
RIP Version 1
• Distance vector
protocol.
• Classful
• No support VLSM
networks.
• No support for
discontiguous
network
RIP Version 2
• Distance vector
protocol.
• Classless.
• Support VLSM
networks.
• Support
discontiguous
network

15. Configuration of RIP v1:-
HYDERABAD#config t
HYDERABAD(config)#no ip routing
HYDERABAD(config)#ip routing
HYDERABAD(config)#router rip
HYDERABAD(config-router)#network 192.168.2.0
HYDERABAD(config-router)#network 10.0.0.0
HYDERABAD(config-router)#exit
HYDERABAD(config)#exit
HYDERABAD#show ip route

16. Configuration of RIP v2:-
HYDERABAD#config t
HYDERABAD(config)#no ip routing
HYDERABAD(config)#ip routing
HYDERABAD(config)#router rip
HYDERABAD(config-router)#version 2
HYDERABAD(config-router)#network
192.168.2.0
HYDERABAD(config-router)#network 10.0.0.0
HYDERABAD(config-router)#exit
HYDERABAD(config)#exit
HYDERABAD#show ip route

17. Autonomous System(AS):-
• An autonomous system (AS) is a group of networks
under a single administrative control, which could be
your company, a division within your company, or a
group of companies.
• Each AS is assigned a unique number in order to
differentiate it from other autonomous systems.
• Range of AS no:-
total AS nos.= 1 - 65535
public AS nos = 1 – 64512
private AS no = 64513 – 65535.

18. Routing protocol classification:-
IGP
• Interior Gateway
Protocol.
• Routing protocols
used within an AS.
• All routers will be
routing within the
same AS boundary.
• IGPs include RIP,
IGRP, EIGRP, OSPF,
and IS-IS.
EGP
• Exterior Gateway
Protocol
• Routing protocols used
between different AS.
• Routers in different AS
need as EGP.
• E.g. BGP is used to
route traffic across the
Internet backbone
between different
autonomous systems.