Assignment: Subnetting
In this assignment, you are required to re-organize our Department’s wired computer network. The first part of the assignment familiarizes you with the current network. The second part requires you to divide the current network into two sub-networks: a small one for the staff and a larger one for the students.
Part 1
Our senior academic Prof Dumbledore’s Departmental desktop has the IP address 29.45.49.74/22. Based on this, please answer the following questions.
What is the network address of this network? [1 mark]
What is the network mask of this network? [1 mark]
What is the broadcast address in this network? [1 mark]
What is the lowest host IP address in this network? [1 mark]
Assuming that the network router is assigned the largest IP address in the range, what is the IP address of the router? [1 mark]
What is the largest host IP address in this network, excluding the router? [1 mark]
What is the maximum number of hosts that can be supported in this network, not counting the router? [1 mark]
Part 2
In this part, you are asked to partition the Departmental network address block to create separate staff and student sub-networks. Your network must be able to support up to 61 machines on the staff network (not counting the router) and up to 419 machines on the student network (also not counting the router). You must choose the largest possible network address for the student network. You must then choose the smallest possible network address for the staff network. You must also choose the smallest possible size for the two sub-networks so that a visitor/guest network can be established in the future with the remaining network capacity.
Part 2A
Based on your partition, please answer the following questions that relate to the student network.
What is the network address of this network? [1 mark]
What is the network mask of this network? [1 mark]
What is the broadcast address in this network? [1 mark]
What is the lowest host IP address in this network? [1 mark]
Assuming that the network router is assigned the largest IP address in the range, what is the IP address of the router? [1 mark]
What is the largest host IP address in this network, excluding the router? [1 mark]
What is the maximum number of hosts that can be supported in this network, not counting the router? [1 mark]
Part 2B
Based on your partition, please answer the following questions that relate to the staff network.
What is the network address of this network? [1 mark]
What is the network mask of this network? [1 mark]
What is the broadcast address in this network? [1 mark]
What is the lowest host IP address in this network? [1 mark]
Assuming that the network router is assigned the largest IP address in the range, what is the IP address of the router? [1 mark]
What is the largest host IP address in this network, excluding the router? [1 mark]
What is the maximum number of hosts that can be supported in this network, not counting the router? [1 mark]
Expert Answer
part 1 :
Network address :
here 22 bits are used for network id.
29.45.49.74 = 0001 1100. 0010 1101. 0011 0001. 0100 1010
Network id : 0001 1100. 0010 1101. 0011 0000. 0000 0000
Network mask :
First 22 bits are 1 in netwrok mask, as 22 bits are used for network id.
network mask : 1111 1111. 1111 1111. 1111 1100. 0000 0000
broadcast address :
network bits remains as it is and all other bits are 1 in broadcast address.
broadcase address : 0000 0000. 0000 0000. 0000 0011. 1111 1111
lowest host IP :
lowest IP is first IP in network which is : 0001 1100. 0010 1101. 0011 0000. 0000 0000
but this IP is assigned as network IP and it is not assigned to any host.
so lowest host IP : 0001 1100. 0010 1101. 0011 0000. 0000 0001
router’s IP :
router is assinged largest IP , which is 0001 1100. 0010 1101. 0011 0011. 1111 1111
but it is also boradcast address and it is not assigned to any host or router.
So, router’s IP largest address except broadcast address.
router’s IP : 0001 1100. 0010 1101. 0011 0011. 1111 1110
largest host ID in network excluding router :
0001 1100. 0010 1101. 0011 0011. 1111 1101
Maximum number of hosts supported :
total IP addresses = 2^10 = 1024
maximum hosts supported = total addresses – broadcast address – network ID – router’s address
= 1024-1-1-1
= 1021.
Part 2 :
Here network is divided into 3 subnetworks.
1) staff network
2) Student Network
3) For Guest and other use.
Network will be divided as shown in below image
– use 23rd bit to divide network into 2 sub networks.
Network IDs of sub networks :
0001 1100. 0010 1101. 0011 0000. 0000 0000 = 28.45.48.0(22 network bits and 1 for subnet)
0001 1100. 0010 1101. 0011 0010. 0000 0000 = 28.45.50.0
student must have largest network(as specified in question)
hence student subnet ID: 0001 1100. 0010 1101. 0011 0010. 0000 0000 = 28.45.50.0
divide the second network in 8 more parts using bits 24, 25, 26 .
Assign one network to staff .
Staff subnet ID : 0001 1100. 0010 1101. 0011 0000. 0000 0000 = 28.45.48.0(22 network bits and 1 for first subnet and another 3 bits for another subnets)
PART 2A :
Network address :
here 23 bits are used for network id.
Network address : 0001 1100. 0010 1101. 0011 0010. 0000 0000 = 28.45.50.0
Network mask :
First 23 bits are 1 in netwrok mask, as 22 bits are used for network id and 1 bit for subnet ID .
subnet mask : 1111 1111. 1111 1111. 1111 1110. 0000 0000
broadcast address :
network and subnet bits remains as it is and all other bits are 1 in broadcast address.
broadcase address : 0000 0000. 0000 0000. 0000 0001. 1111 1111
lowest host IP :
lowest IP is first IP in network which is : 0001 1100. 0010 1101. 0011 0010. 0000 0000
but this IP is assigned as subnet IP and it is not assigned to any host.
so lowest host IP : 0001 1100. 0010 1101. 0011 0010. 0000 0001
router’s IP :
router is assinged largest IP , which is 0001 1100. 0010 1101. 0011 0011. 1111 1111
but it is also boradcast address and it is not assigned to any host or router.
So, router’s IP largest address except broadcast address.
router’s IP : 0001 1100. 0010 1101. 0011 0011. 1111 1110
largest host ID in network excluding router :
0001 1100. 0010 1101. 0011 0011. 1111 1101
Maximum number of hosts supported :
total IP addresses = 2^9 = 512
maximum hosts supported = total addresses – broadcast address – subnet ID – router’s address
= 512-1-1-1
= 509
PART 2B :
Network address :
here 22 bits are used for network id and 23rd bit used to divide firstly and then another 3 bits to divide further.
Network address : 0001 1100. 0010 1101. 0011 0000. 0000 0000 = 28.45.48.0
Network mask :
subnet mask : 1111 1111. 1111 1111. 1111 1111. 1100 0000
broadcast address :
network and subnet bits remains as it is and all other bits are 1 in broadcast address.
broadcase address : 0000 0000. 0000 0000. 0000 0000. 0011 1111
lowest host IP :
lowest IP is first IP in network which is : 0001 1100. 0010 1101. 0011 0000. 0000 0000
but this IP is assigned as subnet IP and it is not assigned to any host.
so lowest host IP : 0001 1100. 0010 1101. 0011 0000. 0000 0001
router’s IP :
router is assinged largest IP , which is 0001 1100. 0010 1101. 0011 0000. 0011 1111
but it is also boradcast address and it is not assigned to any host or router.
So, router’s IP largest address except broadcast address.
router’s IP : 0001 1100. 0010 1101. 0011 0000. 0011 1110
largest host ID in network excluding router :
0001 1100. 0010 1101. 0011 0000. 0011 1101
Maximum number of hosts supported :
total IP addresses = 2^6 = 64
maximum hosts supported = total addresses – broadcast address – subnet ID – router’s address
= 64-1-1-1
= 61
If you have any doubts, you can ask in comment section.