cybersecurity

1. ROUTING AND SWITCHING

2. 2

3. 3
HTTP
TCP
IP
Ethernet
interface
HTTP
TCP
IP
Ethernet
interface
IP IP
Ethernet
interface
Ethernet
interface
SONET
interface
SONET
interface
host host
router router
HTTP message
TCP segment
IP packet IP packet
IP packet
Ethernet frame Ethernet frame
SONET frame

4. 4
Application gateway
Transport gateway
Router
Bridge, switch
Repeater, hub
Frame
header
Packet
header
TCP
header
User
data

5. Repeater
5

6. 6
hub hub
hub
hub

7. 7

8. 8
host host host host host
host host host host host
host
host
Bridge

9. 9
switch
A
B
C
D

10. 10

11. 11
hub hub
hub
switch/bridge
segment segment
segment

12. 12

13. 13

14. 14
A B
switches

15. 15
A B
switches

16. 16
switch
A
B
C
D

17. 17
A
B
C
D
Switch learns how to
reach A.

18. 18
A
B
C
D
When in
doubt,
shout!

19. 19
forward on all but the interface
on which the frame arrived

20. 20

21. 21

22. 22
root
One hop
Three hops

23. 23

24. 24
1
2
3
4
5
6
7

25. 25
1
2
3
4
5
6
7

26. 26
See Section 3.2.2 in the textbook for details and another example

27. 27
Group users based on organizational structure, rather than the
physical layout of the building.

28. 28

29. 29

30. 30
Red VLAN and Orange VLAN
Bridges forward traffic as needed
R
RO RO
O
RO

31. 31
Red VLAN and Orange VLAN
Switches forward traffic as needed
R
O
RO
R
R
R
O
O
O
R O
R R R
O
O
O

32. 32

33. 33

34. Hub/
Repeater
Bridge/
Switch
Router
Traffic isolation no yes yes
Plug and Play yes yes no
Efficient routing no no yes
Cut through yes yes no
34

35. 35