In this assignment, you are required to subnet a Class B network address. Comple
ID: 3589792 • Letter: I
Question
In this assignment, you are required to subnet a Class B network address.
Complete the steps as follows:
Your employer is opening a new location, and the IT director has assigned you the task of calculating the subnet numbers for the new networks.
You have determined that you need 10 subnets for the Class B network beginning with the network ID 178.12.0.0.
How many host bits will you need to use to create the new subnets?
Provide the subnet address, host ranges, and broadcast addresses for each subnet.
After the subnetting is complete, how many unused subnets will be waiting on hold for future expansion?
How many possible hosts can each subnet contain?
What is the new subnet mask?
What is the CIDR notation for this network?
Point values are provided in parentheses after each required item.
Explanation / Answer
For 10 subnet 4 host bits = 2^4 = 16 are required to be borrowed from host.
After the subnetting is complete, how many unused subnets will be waiting on hold for future expansion?
As here only 10 subnet are required but we have borrowed 4 bits which means 16 subnet
so remaining 6 subnet addresses are unused.
So after 10 subnet (below bar is on 1st unused subnet which is 10)
====
1011 0010 (.) 0000 1100(.) 1010 0000(.) 0000 0000 to 1011 0010 (.) 0000 1100(.) 1111 0000(.) 0000 0000
in decimel
178(.)12(.)140(.)0 to 178(.)12(.)240(.)0 <<== Unused subnets.
What is the new subnet mask?
/20 which is 255.255.240.0
CIDR notation:
178.12.0.0/20
178.12.0.0
For Class B subnet mask is /16
i.e 255.255.0.0
1011 0010 (.) 0000 1100(.) 0000 0000(.) 0000 0000 (178.12.0.0)
1111 1111 (.) 1111 1111(.) 0000 0000(.) 0000 0000 (255.255.0.0)
After borrowing 4 bits from the host for 10 subnets:
mask becomes /20 which is
----(borrowed 4 bits)
1111 1111 (.) 1111 1111 (.) 1111 0000 (.) 0000 0000
255(.) 255 (.) 240 (.) 0
==>>Subnet addresses , Host ranges, broadcast addresses for each subnet below
Subnet 0:
1011 0010 (.) 0000 1100(.) 0000 0000(.) 0000 0000 (178.12.0.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.0.0/20
178.12.0.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.15.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.0.1 - 178.12.15.254
Subnet 1:
1011 0010 (.) 0000 1100(.) 0001 0000(.) 0000 0000 (178.12.16.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.16.0/20
178.12.16.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.31.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.16.1 - 178.12.31.254
Subnet 2:
1011 0010 (.) 0000 1100(.) 0010 0000(.) 0000 0000 (178.12.32.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.32.0/20
178.12.32.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.47.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.32.1 - 178.12.47.254
Subnet 3:
1011 0010 (.) 0000 1100(.) 0011 0000(.) 0000 0000 (178.12.48.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.48.0/20
178.12.48.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.63.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.48.1 - 178.12.63.254
Subnet 4:
1011 0010 (.) 0000 1100(.) 0100 0000(.) 0000 0000 (178.12.64.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.64.0/20
178.12.64.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.79.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.64.1 - 178.12.79.254
Subnet 5:
1011 0010 (.) 0000 1100(.) 0101 0000(.) 0000 0000 (178.12.80.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.80.0/20
178.12.80.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.95.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.80.1 - 178.12.95.254
Subnet 6:
1011 0010 (.) 0000 1100(.) 0110 0000(.) 0000 0000 (178.12.96.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.96.0/20
178.12.96.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.111.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.96.1 - 178.12.111.254
Subnet 7:
1011 0010 (.) 0000 1100(.) 0111 0000(.) 0000 0000 (178.12.112.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.112.0/20
178.12.112.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.127.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.112.1 - 178.12.127.254
Subnet 8:
1011 0010 (.) 0000 1100(.) 1000 0000(.) 0000 0000 (178.12.128.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.128.0/20
178.12.128.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.143.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.128.1 - 178.12.143.254
Subnet 9:
1011 0010 (.) 0000 1100(.) 1001 0000(.) 0000 0000 (178.12.144.0)
1111 1111 (.) 1111 1111(.) 1111 0000(.) 0000 0000 (255.255.240.0)
178.12.144.0/20
178.12.144.0 is the subnetwork address(first address is the network address and last is the broadcast address)
total number of host addresses = (2^(32 - 20)) - 2 = (2^12) - 2 = 2046
178.12.159.255 is the broadcast addresses
Remaining are available host addresses in the network
178.12.144.1 - 178.12.159.254