Information & communications technologies. Computer Networks. Week 8. Laboratory work №8. Practice Packet Tracer

1.

Information &
communications
technologies
INF-106
Computer Networks
Week 8

2.

Laboratory work №8
Practice Packet Tracer

3.

4.

Router
● The router is a piece of network hardware that connects a
local network to the internet.
● A router is a device that communicates between the internet
and the devices in your home that connect to the internet.
● As its name implies, it “routes” traffic between the devices
and the internet.

5.

Hub
● A hub is a physical layer networking device which is used to connect multiple
devices in a network.
● They are generally used to connect computers in a LAN.

6.

Switch
● A switch is able to handle the data and knows the specific addresses to send
the message.
● It can decide which computer is the message intended for and send the
message directly to the right computer.
● The efficiency of switch has been greatly improved, thus providing a faster
network speed.

7.

Host
A network host is a computer or other device connected to a computer network.
A host may work as a server offering information resources, services, and
applications to users or other hosts on the network. Hosts are assigned at least
one network address.

8.

IP address
An IP address is a unique address that identifies a device on the internet or a local network.
A MAC (Media Access Control) address, sometimes referred to as a hardware or physical
address, is a unique, 12-character alphanumeric attribute that is used to identify individual electronic
devices on a network.
A subnet mask is a 32 bits address used to distinguish between a network address and a host
address in IP address. A subnet mask identifies which part of an IP address is the network address
and the host address.

9.

IP● Internet
Protocol
Address
● IPv4
● IPv6

10.

11.

Subnet Mask
● A class has eight 1's and so on.

12.

Binary
Numbers

13.

Find Network ID from IP Address
Logical ‘AND’ IP address and subnet mask to get Network ID
For example,
IP address: 192.24.134.23
Find Network ID using default subnet mask of 255.255.255.0 for class C
Find the binary representation of IP address and subnet mask
Logical ‘AND’ with subnet mask
Convert binary to decimal value: Network ID: 192.24.134.0 / 24
IP: 11000000.00011000.10000110.00010111
Sm:11111111. 11111111 .11111111. 00000000

14.

15.

Formulas
To calculate 1st network address:
● 1+ last octet of network address
To calculate broadcast address:
● Find the number of degree of valid host addresses, replace that amount to 1
in 4th octet
To calculate last network address:
● Last octet of broadcast address - 1

16.

Find Number of usable hosts:
1. IP address: 169.174.141.10
Subnet Mask: 255.255.255.240
IP address:
1010100
1
1010111
0
1000110
1
00001010
Subnet Mask:
1111111
1
1111111
1
1111111
1
11110000
Network ID:
169
174
141
0
Prefix: 8+8+8+4=28
In the last part of subnet mask we have 4 zeros, so we get that 2^4=16.
Number of hosts: 16
Number of usable hosts: 16-2=14 (1 addr. for NetID and 1 for broadcast address)
Usable hosts: 169.174.141.1 - 169.174.141.14

17.

Practice
1. Convert IP address to binary: 128.11.3.31
1. Convert IP address to decimal:
10101001.10101110.00001010.00000000
1. Convert IP address to binary: 19.244.47.118
1. Convert IP address to decimal:
00100100.10010000.00111011.11100101

18.

Answers
1) 128.11.3.31.
1) 169.174.10.0
2) 00010011.11110100.00101111.01110110
3) 36.144.59.229

19.

Practice _ Network ID
1. Mask: 255.255.248.0
IP address: 192.168.40.50
What is the Network ID?
1. Mask: 255.255.248.0
IP address: 192.168.45.55
What is the Network ID?
1. Mask: 255.255.255.192
IP address: 192.168.45.55
What is the Network ID?

20.

Answers. Easy way to find Network ID
1. IP address: 192.168.40.50
Subnet Mask: 255.255.248.0
Prefix:11111111.11111111.11111000.00000000 = 8+8+5=21
the prefix size is the number of addresses available for use.
We can use: 192.168 (because subnet mask: 255.255.)
So 40 in binary:
00101000.00110010
3rd octet mask bits:11111000.00000000
00101000.00000000
Network ID:192.168.40.0 /21

21.

Answer 2
2. IP address: 192.168.45.55
Subnet Mask: 255.255.248.0
Prefix: 11111111.11111111.11111000.00000000 = 8+8+5=21
We can use: 192.168 (because subnet mask: 255.255.)
So 45 in binary:
00101101.00110111
3rd octet mask bits:11111000.00000000
00101000.00000000
Network ID:192.168.40.0 /21

22.

Answer
3.
IP address: 192.168.45.55
Subnet Mask: 255.255.255.192
Prefix: 11111111.11111111.11111111.11000000= 8+8+8+2=26
We can use: 192.168.45 (because subnet mask: 255.255.255.)
So 55 in binary:
00110111
4th octet mask bits:11000000
00000000
Network ID:192.168.45.0 /26

23.

Practice_ Find Number of usable hosts:
IP address: 19.244.47.118
Subnet Mask: 255.255.255.224
Number of hosts ?
Number of usable hosts ?

24.

Answer
IP address: 00010011.11110100.00101111.01110110
Subnet Mask: 11111111. 11111111.11111111. 11100000
Prefix: 8+8+8+3=27
after ‘and’ 01100000 = 96
Network IP (ID):19.244.47.96
In the last part of subnet mask we have 5 zeros, so we get that 2^5=32.
Number of hosts: 32
Number of usable hosts: 30 (-2 addresses: NetID and broadcast)
Usable hosts: 19.244.47.97 - 19.244.47.126

25.

Questions?