networking 1 routing - weblearn.hs-bremen.de file8 15 routing mns chapter 1, prof. dr. richard...

1

1

Routing

MNS Chapter 1, Prof. Dr. Richard Sethmann, Hochschule Bremen, FB E&I

Networking

Routing

Prof. Dr. Richard Sethmann

Hochschule Bremen University of Applied Sciences

Fachbereich Elektrotechnik und InformatikMaster in Digital Media

2

Routing


Content

• Introduction• Distance Vector Protocols (RIP, IGRP)• Link-State Routing Protocols (OSPF)• Summary

2

3

Routing


The Task

Send an email from user A in Germany to user B in India.

4

Routing


Encapsulation

3

5

Routing


IP Header

6

Routing


Network Layer Devices

4

7

Routing


Internet Routing

• Internetworks are divided into domains, or autonomous systems (AS)

• Packets are routed inside an AS and between different AS

• Different types of autonomous systems such as – Single homed, – Multihomed nontransit (big companies), and – Multihomed transit (Provider).

8

Routing


Autonomous Systems

5

9

Routing


Interior Gateway Protocols (IGP)Exterior Gateway Protocols (EGP)

10

Routing


Interior Gateway Protocols (IGP)

• IGPs route data within an autonomous system• IGPs

– Routing Information Protocol (RIP) and (RIPv2) – Interior Gateway Routing Protocol (IGRP) – Enhanced Interior Gateway Routing Protocol (EIGRP) – Open Shortest Path First (OSPF) – Intermediate System-to-Intermediate System protocol

(IS-IS)

6

11

Routing


Exterior Gateway Protocols (EGP)

• EGPs route data between autonomous systems– An example of an EGP is Border Gateway Protocol

(BGP)

12

Routing


Single-Homed Autonomous Systems

7

13

Routing


Multihomed NontransitAutonomous Systems

14

Routing


Multihomed Transit Autonomous Systems

EBGP: Exterior Border Gateway Protocol

IBGP: Interior Border Gateway Protocol

8

15

Routing


Default Route

Reduces complexity

Used in most situations

16

Routing


Distance in Metrics

Reduces complexity

Used in most situations

9

17

Routing


Routing Metrics

18

Routing


Administrative Distance

10

19

Routing


Administrative Distance

20

Routing


Convergence

11

21

Routing


Convergence

• When all routers in a network agree on the topology they are considered to have converged.

• Dependent on the routing protocol in use, a significant amount of time may pass before all the routers in a network converge.

22

Routing


Routing Table

• Every computer with network interface card possesses a routing table

• Contains all information about path finding • Allocated in RAM• Entries

– Networking address– Subnet mask– Gateway address– Interface – Metric

12

23

Routing


Static Routes

24

Routing


Static Routes

• Must be configured manually• Very little CPU load• No bandwidth needed• Any network topology changes require the

network administrator to add and delete static routes to account for the changes.

• Could require a tremendous amount of administrative time

• Very safe

13

25

Routing


Dynamic Routes

• Routing table is updated automatically after topology changes

• CPU load and memory usage• Scalability • Bandwidth needed• Not secure due to routing updates sent

unencrypted over the network

26

Routing


RIP

14

27

Routing


RIP - Network Discovery

28

Routing


RIP - Topology Changes

15

29

Routing


RIP - Routing Loops

30

Routing


RIP – Counting to Infinity

16

31

Routing


RIP –Maximum Hop Count

32

Routing


RIP – Split Horizon

17

33

Routing


RIP – Hold-Down Timers

34

Routing


IGRP

• Distance Vector Protocol• Metric: bandwidth, load, delay, reliability, • By default, routing updates are broadcasted

every 90 seconds

18

35

Routing


IGRP - Metric

36

Routing


IGRP - Metric

19

37

Routing


OSPF

38

Routing


OSPF

20

39

Routing


OSPF

40

Routing


OSPF

21

41

Routing


OSPF

Present Dijkstra Algorithmhttp://www.dgp.toronto.edu/people/JamesStewart/270/9798s/Laffra/DijkstraApplet.html

42

Routing


Thank you very much for your attention.

networking 1 routing - weblearn.hs-bremen.de file8 15 routing mns chapter 1, prof. dr. richard...

Documents