1. The document discusses different types of networking devices like repeaters, bridges, routers, and gateways and how they operate at different layers of the OSI model. 2. It provides examples of how these devices like repeaters, bridges, and routers are used to connect different local area networks and extends the physical length and coverage of a network. 3. The document also discusses concepts like routing tables, link state routing, and the Dijkstra algorithm that are used to determine the best paths between nodes in a network.

1. Connecting devices
2
1
Networking Repeaters
Bridges devices
Connecting
devices
3 4
Internetworking
Gateways Routers
devices

2. Connection devices with the OSI
model
7 layers of OSI model
All 7 layers
1 Layer
Physical data link, Physical +
Physical
Network Layers Datalink layer
3 layers
2 layers
Gateway Router Bridge Repeater

3. A repeater in the OSI model
Device A Device B
Repeater
Subnet R Subnet
7 7
OSI LAYERS
OSI LAYERS
6 6
5 5
4 4
3 3
2 2
Repeater extends the physical
1 length of a network
1
R

4. A repeater
Frame
Repeater B
A
D C

5. Repeater Functions
Regenerate Corrupted Regenerates Corrupted Signal
Repeater
Corrupted Signal Regenerate Corrupted

6. Bridge to connect two LANs
LAN 1 LAN 2
A A
HUB HUB
B B
Bridge
C C
D D

7. A Bridge in the OSI model
Device A Device B
Repeater
Subnet R Subnet
7 7
OSI LAYERS
OSI LAYERS
6 6
5 5
4 4
3 3
2 2
1 1
1 Data link
2 Physical

8. Functions of a Bridge
Seg ment 1
Packet
A B
Bridge
e nt 2
Se gm
C Packet
D

9. Three types of bridges
I. Simple bridges
I. Learning bridges
I. Multiport bridges

10. Simple bridge - 1
• Primitive type
• Least expensive
• Links two segments
• Contains a table that lists the addresses of
all the stations in each of them
• Addresses are to be entered manually
• Before functioning the operator must set
down & program the addresses of every
station

11. Use of routers to connect LANs
Server
Device 4
Device 1
Token Ethernet Server
ring hub hub
Device 2
Device 5
Bridge
Device 3
Device 6

12. A router in the OSI Model
Device Repeater Device
A
B
Network R Network
7 7
OSI LAYERS
OSI LAYERS
6 6
5 5
4 4
3 3
2 2
Network
1 1
Data link
Physical

13. Routers in an internet
Router
Network B
Network A
Router
Router
Router
Network E
Network C
Router
Router
Network D

14. Route for the packets from
network A to network D
Network B Network C
Network A
Network D
Network Q

15. Use of gateways (connecting
LANs and Mainframe)
Front-
end
Server Device 4
Main
frame
Device 1 Server
Token
Ethernet
ring hub
hub
Device 2 Device 5
Device 3
D i 6

16. A Gateway in the OSI model
Device Device
Network Gateway Network
A B
7 7 7
OSI LAYERS
OSI LAYERS
6 6 6
5 5 5
4 4 4
3 3 3
2 2 2
1 1 1

17. Routing table
An inter net
05 1 _ 08 1 _
24 1 _ 25 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R1 10 1 _
R5 08 1 _ R3
LA
N 24 36 1 _
53 1 _
LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

18. Updating the table
R,’s old table
05 1 _
24 1 _ 05 1 _
36 1 _ 05 2 R2 05 1 _
08 2 R2 08 2 R2
Received from R2 After adjustment 24 1 _ 24 1 _
08 1 _ + one 08 2 R2 36 1 _ 36 1 _
05 1 _ hop 05 2 R2 Combined R,’s new tabl

19. Updating the table
R,’s old table
10 1 _
08 1 _ 08 1 _
10 1 _ 08 1 _
Received from R2 After adjustment 10 2 R4 10 1 _
10 2 R4 18 2 R4
18 1 _ + one 18 2 R4
10 1 _ hop 10 2 R4 Combined R,’s new tabl

21. Updated routing tables for R1, R5
Routing table & R6
05 1 08 1 _
08 2 R2
25 1 _
24 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R5 08 1 _
R1 10 1_ R3
18 2 R4
LA 05 2R1
N 24 08 3 R1
24 2R1
36 1_
53 1_ LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

22. Routing table
Final routing tables
05 1 08 1 _
08 2 R2
25 1 _
24 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R5 08 1 _
R1 10 1_ R3
18 2 R4
LA 05 2R1
N 24 08 3 R1
24 2R1
36 1_
53 1_ LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

23. Cost in link state routing
Routing table
05 1 _ 08 1 _
24 1 _ 25 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R1 10 1 _
R5 08 1 _ R3
LA
N 24 36 1 _
53 1 _
LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

24. The flooding of R2 ‘s LSP
Routing table
05 1 _ 08 1 _
24 1 _ 25 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R1 10 1 _
R5 08 1 _ R3
LA
N 24 36 1 _
53 1 _
LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

25. The flooding of R2 ‘s LSP
Routing table
05 1 _ 08 1 _
24 1 _ 25 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R1 10 1 _
R5 08 1 _ R3
LA
N 24 36 1 _
53 1 _
LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

26. Costs in the Dijkstra algorithm
Routing table
05 1 _ 08 1 _
24 1 _ 25 1 _
36 1 _ LAN5 LA
R2 N8
LAN36 LAN53
R1 10 1 _
R5 08 1 _ R3
LA
N 24 36 1 _
53 1 _
LAN10
LAN18 R4
R5 18 1 _
18 1 _ 10 1 _
24 1 _

27. Networks 5, 36, 24 added
LAN5
1
LAN36
R1 3
Root LAN24
2

28. (ii) R2 added ; 5 permanent
LAN5
R2
1
LAN36
R1 3
Root LAN24
2

29. (iii) R2 permanent, 55 added
LAN5
R2
1
3
LAN36
R1 3
LAN55
Root LAN24
2

30. (iv) 24 permanent, R5 added
LAN5
R2
1 3
LAN55
R1 3 LAN36
Root
LAN24
2
R5

31. (v) R5 permanent, 18 added
LAN5
R2
1 3
LAN55
R1 3 LAN36
Root
LAN24
2
R5 LAN18

32. Dijkstra algorithm
5 R2 55
LAN36 LAN53
R1
R5 R3
2 3
LA
N 24
10
LAN18 R4
9
R5

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