hi please use it

3. Hardware and software such as…
laptop
Switch
Router
wireless accesspoint
cabling used to connect the
devices Email hosting
web hosting services.
NOS

4.  In simple terms,
a network device is a physical device that is used
to connect other physical devices on a network.
 In some cases, their role is to simply forward
packets of information to a destination.
 In other cases, it might be to serve as a
translator or to block suspicious network
traffic.

5. Physical Components of the Network:
End Devices or Hosts:
Make interface between usersand the underlying
communication network.
Computers(Server or client)
Network printers
VoIP phones
Mobile handheld devices
Workstation
A host device used as source or destination of a message
transmitted over the network

6. Intermediary Network Devices:
Used to connect the individual hosts to the
network and can connect multiple individual
networks to form an internetwork.
Switches
Wirelessaccesspoint
Router
Firewalls
Hub
Bridge
Gateway
Useto determine the path that messagesshould
take through the network

7. Network Media:
The medium provides the channel over which the
message travels from source to destination.
The three types of media are
Copper/twisted pair/coaxial cable
Fiber Optic cables
Wireless.

9. Network Representations

10. Network Interfaces Card (NIC):
It provides interface between computer’s internal
system resources and external network resources
NIC has unique physical address(MAC address)

11. Client:
The device an end user usesto accessa network.

12. Server:
A devicesprovides resourcesto a network. (Email, Web
pages,or files)

13. Repeaters
Repeaters clean, amplify, and resend signals that are
weakened by long cable length.

15. Bridges
At layer 1
,it is used to regenerate a signal and filter
traffic on a LAN
To provide security, it Filters traffic by looking at
the MAC address and prevent unauthorized access.

18. Difference between repeater and bridge:
Repeaters retransmit frames to all the connected
devicesin a network, while
Bridges transmit frames only to the segment in which
device with MAC addressspecified in frame ispresent

19. Hub
Hubs isa central network device that connects
network nodesand provide central network
management..
They connects devices centrally in a star topology.
They cannot filter network traffic.
They cannot determine best path

20. Active hub
Active hubswork similar to repeaters.
Also called multiport repeater.
A passive hub
serves simply provides connection between devices,
enabling data to go from one device (or segment) to
another.
Intelligent hubs/manageable hub

21. Switches
It provides bridging with greater efficiency.
They have buffer for each link to which it isconnected

22. Store and Forward Switches:
Do error checking on each frame after the entire frame
has arrived into the switch
It stores the frame into buffer until whole packet arrives
The switch looks in its MAC address table for the port to
which to forward the destination device.
Highly reliable because doesn’t forward bad frames
Slower than other types of switches because it holds on
to each frame until it is completely received to check for
errors before forwarding

23. Cut Through Switches
Faster than store and forward because doesn’t perform
error checking on frames
It Forwards bad frames too
Reads addressinformation for each frame as the
frames enter the switch.
After looking up the port of the destination device,
frame isforwarded without waiting for entire packet to
arrive.

24. Router
Different networks can be connected via routers.
It storesIP addressof the devices of networks in a table
called routing table
Function of router isto receive packets from one
network and forward to another network based on
information stored in routing table

25. Routing strategies:
Adaptive Routing
In adaptive routing, a router may select new route for
each packet
Non Adaptive Routing
In non adaptive routing router choose same path for all
the packets whose destination issame.
Routing table contains:

26. Static router:
They usesame path for all packets of same destination.
More secure.
Needsto maintain manually.
Can not updated automatically.
Dynamic router:
It usesa routing protocol to select best pathsfor packets
Each packet issent via different path
Lesssecure.
Can be updated and Maintained automatically

27. Gateway
It isalso called protocol converter.
It isused to connect two different network types.
It differ from router by:…
Router connects networks having implemented similar
protocols.
Gateways used to connect two different networks
implemented using different protocols.

28. AccessPoints
used to connectsdirectly to a wired LAN and then
provideswirelessconnections
It acts as a HUB between wired and wireless networks
It provides security and extend physical range of LAN

29. Media:

30. Modem(Modulation and Demodulation)
Digital to analogue signal from the sender
(Modulation) and analogue to digital signal
at the receiver side(Demodulation)

31. There are various types of computer
networks
Based on the geographical area covered
and data transfer rate
Local Area Network
Metropolitan Area Network
Wide Area Network

32. Local Area Network
It isa network that connects
Computers
mobile phones
Tablet
Mouse
Printer
limited distance(100m)

33. Userscan print documents using a connected
Printer
Upload/download documents and software to
and from the local server.
Short range communication with the high speed
data transfer rates
10Mbps (called Ethernet) to 1000 Mbps

34. Metropolitan Area Network (MAN)
Extended form of LAN which covers a larger
geographical area like a city or a town.
Data transfer rate in MAN alsoranges in Mbps,less
comparable with the LAN
Extended up to 30-40 km

35. Wide Area Network (WAN)
Connects computers and other LANs and MANs, which
are spread across different geographical locations of a
country or in different countries or continents.

37. Network Resource

38. Network Resource

39. Network Resource

40. Cont’…

41. Cont’…

42. Cont’…

44. Wired Network Topology

45. Cont’…

46. Cont’…

47. Cont’…

48. Cont’…

51. The process of subnetting is both a mathematical
process and a network design process.
Mathematics focus
How subnets are
calculated? How subnet is
identified?
How sub net isassigned?
The network design focuson,
How many subnets are needed?
How many hosts an individual subnet needed?

52. An IP address isa thirty-two(32)-bit binary number.
The thirty-two bits are separated into four groups(4)
of eight bits called octets.
example

53. Subnetting is the process of taking an IP network and
dividing it into smaller IP networks subnets.
Every subnet, has broadcast domain or broadcast traffic
Broadcast traffic is network traffic that has a single
source but is destined(chosen for particular purpose) for
all hosts within a subnet

54. Without Subnets
Having a single broadcast domain
Increased Network Congestion (overcrowding )
Broadcast traffic is very inefficient and consumes large
amounts of resources
Reduced Network Security:
Broadcast Domain can reduce network security by
increasing the risk of unauthorized access and network
attacks

55. The Need for Subnets
What the solution?
Break the single broadcast
domain into smaller broadcast
domains.
The devices connected to each
broadcast domain issmaller.
This, improving the performance
of all deviceson the network.

56. How subnetting?
The host bits are changed to
network bits.
By borrowing host bits, more
IP subnets are created, but
each subnet can support
fewer hosts.
A binary 0 in the subnet
mask means that bit is part
of the host portion of an IP
address
A binary 1 in the subnet
mask means that bit is part
of the network portion of an
IP address
So, to change a bit from
a host bit to a network
bit, the binary value of
the bit must be changed
from 0 to 1in the subnet
mask.

57. 1. Determine the assigned IP address space.
2. Determine the number of subnets required based on
the design of the existing network
3. Determine how many hosts each subnet can support.
4. Calculate the decimal value and prefix value of the
new subnet mask
5. Calculate the network address of the new possible
Subnets address(NWID)
Broadcast address for each possible subnet, and the
Range of usable IP addresses in each possible subnet.
6. Assign IP addressesto all devices

58. Cont’…

59. • To calculate the number of possible subnets, use the
formula 2 power of b, where b equals the number of
host bits borrowed.
• For example, if three host bits are borrowed, then n=3 ,2
the power of 3 = 8, so eight subnets are possible if three
host bits are borrowed.

60. To determine how many host bits need to be borrowed
and rewrite the formula as 2 power of b > (number
of required subnets).
For example, if the number of required subnets is 18,
then write the formula as2 power of b >18.
Solve for b by getting as close to the number of
required subnets as possible.
In this example, b =5 (2 power of 5 =32).
This means that to create at least 18subnets, 5 host bits
must be borrowed

61. A. Determine the assigned IP addressspace.
B. Determine number of default host bitsavailable.
C. Determine number of host bitsborrowed.
D. Determine the number of remaining host bits by
subtracting the number of host bits borrowed from
the default number of host bits.
E. Determine the number of possible hosts by using the
formula 2 power r - 2.
F. Calculate the new subnet mask and prefix

62. How to calculate:
A. Determine the classof IP network.
B. Determine the default subnet mask or prefix for the
classof address.
C. Determine how many host bits were borrowed or
given to the network
D. Calculate the new subnet mask and prefix
To calculate the new subnet mask, start with the first
binary 0 in the default subnet mask and change it to a
binary 1. Continue doing this, moving left to right, for
the number of bits borrowed.

63. Calculate the Broadcast Address and Usable
Range of the New Subnets
Once the network addressof the new possible
subnets isknown,
The broadcast address
The usable range for the new subnets can be quickly
calculated.
To calculate the broadcast address and each of the subnets,
identify the next subnet, and then go back one address.

64. Cont’…

65. Usable Range of the New Subnets
• To calculate the usable range of IP addresses meaning,
the range of IP addresses that can be assigned to
devices connected to the subnet.
Do the following:
1. Add one addressto the subnet addressto find the first
usable IP address.
2. Subtract one address from the broadcast address to
find the last usable IP address.
The following table shows all of the
New possible subnets
The usable range of IP addressesfor each subnet; and
The broadcast addressfor each subnetting

66. Cont’…