IP Subnet worksheet

1. Network (CIDR): 253.184.2.0/28

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{253.184.2.4}$$=\text{11111101.10111000.00000010.00000100}$

2. A /28 mask is 28 one-bits (the network part) followed by 4 zero-bits (the host part)

   $\text{/28}$$=\text{11111111.11111111.11111111.11110000}$$=\text{255.255.255.240}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{11111101.10111000.00000010.00000100 AND 11111111.11111111.11111111.11110000}$$=\text{11111101.10111000.00000010.00000000}$$=\text{253.184.2.0/28}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{253.184.2.0 OR 0.0.0.15}$$=\text{253.184.2.15}$

5. 4 host bits give 2 to the power of 4 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^4-2$$=14$

2. Network (CIDR): 102.17.2.16/28

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{102.17.2.18}$$=\text{01100110.00010001.00000010.00010010}$

2. A /28 mask is 28 one-bits (the network part) followed by 4 zero-bits (the host part)

   $\text{/28}$$=\text{11111111.11111111.11111111.11110000}$$=\text{255.255.255.240}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{01100110.00010001.00000010.00010010 AND 11111111.11111111.11111111.11110000}$$=\text{01100110.00010001.00000010.00010000}$$=\text{102.17.2.16/28}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{102.17.2.16 OR 0.0.0.15}$$=\text{102.17.2.31}$

5. 4 host bits give 2 to the power of 4 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^4-2$$=14$

3. Network (CIDR): 46.135.0.0/20

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{46.135.1.14}$$=\text{00101110.10000111.00000001.00001110}$

2. A /20 mask is 20 one-bits (the network part) followed by 12 zero-bits (the host part)

   $\text{/20}$$=\text{11111111.11111111.11110000.00000000}$$=\text{255.255.240.0}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{00101110.10000111.00000001.00001110 AND 11111111.11111111.11110000.00000000}$$=\text{00101110.10000111.00000000.00000000}$$=\text{46.135.0.0/20}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{46.135.0.0 OR 0.0.15.255}$$=\text{46.135.15.255}$

5. 12 host bits give 2 to the power of 12 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^{12}-2$$=\mathrm{4,094}$

4. Network (CIDR): 47.48.1.0/24

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{47.48.1.7}$$=\text{00101111.00110000.00000001.00000111}$

2. A /24 mask is 24 one-bits (the network part) followed by 8 zero-bits (the host part)

   $\text{/24}$$=\text{11111111.11111111.11111111.00000000}$$=\text{255.255.255.0}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{00101111.00110000.00000001.00000111 AND 11111111.11111111.11111111.00000000}$$=\text{00101111.00110000.00000001.00000000}$$=\text{47.48.1.0/24}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{47.48.1.0 OR 0.0.0.255}$$=\text{47.48.1.255}$

5. 8 host bits give 2 to the power of 8 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^8-2$$=254$

5. Network (CIDR): 234.177.1.0/24

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{234.177.1.15}$$=\text{11101010.10110001.00000001.00001111}$

2. A /24 mask is 24 one-bits (the network part) followed by 8 zero-bits (the host part)

   $\text{/24}$$=\text{11111111.11111111.11111111.00000000}$$=\text{255.255.255.0}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{11101010.10110001.00000001.00001111 AND 11111111.11111111.11111111.00000000}$$=\text{11101010.10110001.00000001.00000000}$$=\text{234.177.1.0/24}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{234.177.1.0 OR 0.0.0.255}$$=\text{234.177.1.255}$

5. 8 host bits give 2 to the power of 8 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^8-2$$=254$

6. Network (CIDR): 12.136.2.12/30

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{12.136.2.14}$$=\text{00001100.10001000.00000010.00001110}$

2. A /30 mask is 30 one-bits (the network part) followed by 2 zero-bits (the host part)

   $\text{/30}$$=\text{11111111.11111111.11111111.11111100}$$=\text{255.255.255.252}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{00001100.10001000.00000010.00001110 AND 11111111.11111111.11111111.11111100}$$=\text{00001100.10001000.00000010.00001100}$$=\text{12.136.2.12/30}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{12.136.2.12 OR 0.0.0.3}$$=\text{12.136.2.15}$

5. 2 host bits give 2 to the power of 2 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^2-2$$=2$

7. Network (CIDR): 2.213.1.0/26

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{2.213.1.16}$$=\text{00000010.11010101.00000001.00010000}$

2. A /26 mask is 26 one-bits (the network part) followed by 6 zero-bits (the host part)

   $\text{/26}$$=\text{11111111.11111111.11111111.11000000}$$=\text{255.255.255.192}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{00000010.11010101.00000001.00010000 AND 11111111.11111111.11111111.11000000}$$=\text{00000010.11010101.00000001.00000000}$$=\text{2.213.1.0/26}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{2.213.1.0 OR 0.0.0.63}$$=\text{2.213.1.63}$

5. 6 host bits give 2 to the power of 6 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^6-2$$=62$

8. Network (CIDR): 216.77.0.0/22

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{216.77.1.6}$$=\text{11011000.01001101.00000001.00000110}$

2. A /22 mask is 22 one-bits (the network part) followed by 10 zero-bits (the host part)

   $\text{/22}$$=\text{11111111.11111111.11111100.00000000}$$=\text{255.255.252.0}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{11011000.01001101.00000001.00000110 AND 11111111.11111111.11111100.00000000}$$=\text{11011000.01001101.00000000.00000000}$$=\text{216.77.0.0/22}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{216.77.0.0 OR 0.0.3.255}$$=\text{216.77.3.255}$

5. 10 host bits give 2 to the power of 10 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^{10}-2$$=\mathrm{1,022}$

9. Network (CIDR): 150.58.0.0/18

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{150.58.2.11}$$=\text{10010110.00111010.00000010.00001011}$

2. A /18 mask is 18 one-bits (the network part) followed by 14 zero-bits (the host part)

   $\text{/18}$$=\text{11111111.11111111.11000000.00000000}$$=\text{255.255.192.0}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{10010110.00111010.00000010.00001011 AND 11111111.11111111.11000000.00000000}$$=\text{10010110.00111010.00000000.00000000}$$=\text{150.58.0.0/18}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{150.58.0.0 OR 0.0.63.255}$$=\text{150.58.63.255}$

5. 14 host bits give 2 to the power of 14 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^{14}-2$$=\mathrm{16,382}$

10. Network (CIDR): 197.153.1.0/26

1. Write the address in binary (ones and zeros), 8 bits for each of the four numbers, so you can see each bit

   $\text{197.153.1.13}$$=\text{11000101.10011001.00000001.00001101}$

2. A /26 mask is 26 one-bits (the network part) followed by 6 zero-bits (the host part)

   $\text{/26}$$=\text{11111111.11111111.11111111.11000000}$$=\text{255.255.255.192}$

3. Keep the address bits where the mask is 1 and set the rest to 0 (a bitwise AND). That leaves the network address

   $\text{11000101.10011001.00000001.00001101 AND 11111111.11111111.11111111.11000000}$$=\text{11000101.10011001.00000001.00000000}$$=\text{197.153.1.0/26}$

4. Set every host bit to 1 to get the broadcast address, the last one in the block (network OR wildcard mask)

   $\text{197.153.1.0 OR 0.0.0.63}$$=\text{197.153.1.63}$

5. 6 host bits give 2 to the power of 6 addresses. Take away 2, because the network and broadcast addresses can't be given to devices

   $2^6-2$$=62$