Network Address and Subnetting

This study material provides an overview of network address and subnetting. It covers topics such as calculating network addresses, subnet masks, and available addresses for hosts. Examples and calculations are included to help understand the concepts.

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Question Number Mark
allocate
d
Mark
earne
d
Question 1: (3 marks) 3
a
)
b
)
c
)
Network address for the IP address 156.120.32.3/26
156.120.32.0/26
Direct Broadcast address
156.120.32.63
Range of address available for hosts
156.120.32.1 - 156.120.32.62
Calculation:
The following table is used for the calculation of number of bits used for subnetting.
Subnet
Mask
0 128 192 224 240 248 252 254 255
No. of bits used for
subnetting (n)
0 1 2 3 4 5 6 7 8
Subnet
IP address = 156.120.32.3
Subnet mask = 255.255.255.192
1 mark
each
item,
total 3

Total bits = 8
Number of bits used for subnetting = 2
Therefore number of bits left for host = 8 – 2
= 6
Value of last bit used for subnet masking = 2^6
= 64
Number of host per subnet = 64 -2
= 62
Question 2: (8 marks) 8
a
)
Block of address granted to the company is 128.32.16.8/22
Network address for this block is 128.32.16.0/22, and the total addresses the block
contains including special addresses is 1024.
1
b
)
Subnet No. addresses Subnet address Mask /n
1 128 128.32.16.0 /24
2 64 128.32.17.0 /25
3 32 128.32.17.128 /26
4 32 128.32.17.192 /26
Calculations:
IP address = 128.32.16.8/22
Binary Representation = 10000000.00100000.000100 00.00001000
Subnet mask = 255.255.252.0
Binary Representation = 11111111.11111111.111111 00.00000000
Network: 128.32.16.0/22 10000000.00100000.000100 00.00000000 (Class B)
6
c
)
After the allocation of the subnet 518 number of addresses are left unallocated.
Total number of IP address available for the Subnet = 1022
1

Allocated IP address for subnet 1 = 254
Allocated IP address for subnet 1 = 126
Allocated IP address for subnet 1 = 62
Allocated IP address for subnet 1 = 62
Therefore, total number of IP address allocated = 254 +126 + 62 + 62
= 504
Hence, The remaining IP address for the subnet = 1022 -504
= 518
Question 3: (4 marks) 4
a
)
i)
ii
)
The frame is carrying (UDP/IPv4) message. The destination host domain name is
sns.dns.icann.org.
TCP protocol is used for the in the frame 644.
From the analysis of the few more frames down the general activity of the user is
analysed and it is found that different protocols are used for accessing the
destination address. In the frame 644 a HTTP request is sent to the server for
establishment of TCP connection and in the frame 647 another HTTP request is sent
for establishing UDP connection.
1 mark
each
item,
total 2
for 3a.
b
)
The line 2 and 8 is analysed for determining the application running over the two
connection and it is found that the application uses TCP protocol for transmitting
data in the network. For the 2nd 8479 port is used for sending the data packet and it
reaches the destination server using the port 443 i.e. it uses secure HTTPS protocol
over TLS/SSL. For the 8th line port 80 is used for www (world wide web).
1

c
)
The TRACERT command is used for analysing the path used by the source host to
reach the destination address. The command prompt is used for performing the
TRACEROUTE to reach the website www.bom.gov.au and it is found that 8 hops
are needed to be passed for reaching the destination address. Here the IP address of
the gateway device through the packet is sent to the destination server is 10.10.30.1
and the destination IP address is 23.58.66.44.
1
Total marks awarded 15
(max)
Less late penalties
Less plagiarism penalties
Total marks earned
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Bibliography
Lammle, T. (2016). CCNA Routing and Switching Complete Deluxe Study Guide: Exam 100-105, Exam
200-105, Exam 200-125. John Wiley & Sons.
Loo, J., Mauri, J. L., & Ortiz, J. H. (Eds.). (2016). Mobile ad hoc networks: current status and future trends.
CRC Press.
Medhi, D., & Ramasamy, K. (2017). Network routing: algorithms, protocols, and architectures. Morgan
Kaufmann.
Sgambelluri, A., Giorgetti, A., Cugini, F., Bruno, G., Lazzeri, F., & Castoldi, P. (2015, March). First
demonstration of SDN-based segment routing in multi-layer networks. In Optical Fiber
Communications Conference and Exhibition (OFC), 2015 (pp. 1-3). IEEE.