Host Range

Host Range

Example 1:
What valid host range is the IP address 10.22.188.55 255.255.240.0 a part of?
Example 2:
What valid host range is the IP address 172.17.52.88 255.255.254.0 a part of?
Example 3:
What valid host range is the IP address 172.18.25.59 255.255.252.0 a part of?
Example 4:
What valid host range is the IP address 172.18.75.219 255.255.248.0 a part of?
Example 5:
What valid host range is the IP address 172.23.144.133/24 a part of?
Example 6:
What valid host range is the IP address 172.25.155.112 255.255.255.0 a part of?
Example 7:
What valid host range is the IP address 172.26.85.2/26 a part of?
Example 8:
What valid host range is the IP address 172.26.229.139/22 a part of?
Example 9:
What valid host range is the IP address 172.26.237.115/21 a part of?
Example 10:
What valid host range is the IP address 172.27.80.39 255.255.254.0 a part of?
Example 11:
What valid host range is the IP address 192.168.70.38/30 a part of?
Example 12:
What valid host range is the IP address 192.168.166.57 255.255.255.192 a part of?

Class A

Example 1:

What valid host range is the IP address 10.22.188.55 255.255.240.0 a part of?

Solution:

Class A addresses use a default mask of 255.0.0.0
Given subnet mask = 255.255.240.0 (/22)
Valid subnets = 256 – 240 = 16, which means we have a block
size of 16 in the third octet.
Count by 16 until reaching 188.
Subnets are 0, 16, 32, … , 160, 176, 192 etc.
Address 188 falls in the 176 subnet.
Subnet = 10. 22. 176. 0
Next subnet address = 10. 22. 192. 0/22 
Broadcast address is 10. 22. 191. 255/22 of 10. 22. 176. 0/22 network.
Valid host range = 10. 22. 176. 1 to 10. 22. 191. 254

Class B

Example 2:

What valid host range is the IP address 172.17.52.88 255.255.254.0 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.254.0 (/23)
Valid subnets = 256 – 254 = 2, which means we have a block size of 2 in the third octet.
Count by 2 until reaching 52.
Subnets are 0, 2, 4, … , 50, 52, 54 etc.
Address 52 falls in the 52 subnet.
Subnet = 172. 17. 52. 0
Next subnet address = 172. 17. 54. 0/23
Broadcast address is 172. 17. 53. 255/23 of 172. 17. 52. 0/23 network.
Valid host range = 172. 17. 52. 1 to 172. 17. 53. 254

Example 3:

What valid host range is the IP address 172.18.25.59 255.255.252.0 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.252.0 (/22)
Valid subnets = 256 – 252 = 4, which means we have a block size of 4 in the third octet.
Count by 4 until reaching 25.
Subnets are 0, 4, 8, 12, 16, 20, 24, 28 etc.
Address 25 falls in the 24 subnet.
Subnet = 172. 18. 24. 0
Next subnet address = 172. 18. 28. 0/22
Broadcast address is 172. 18. 27. 255/22 of 172. 18. 24. 0/22 network.
Valid host range = 172. 18. 24. 1 to 172. 18. 27. 254

Example 4:

What valid host range is the IP address 172.18.75.219 255.255.248.0 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.248.0 (/21)
Valid subnets = 256 – 248 = 8, which means we have a block size of 8 in the third octet.
Count by 8 until reaching 75.
Subnets are 0, 8, 16, … , 72, 80 etc.
Address 75 falls in the 72 subnet.
Subnet = 172. 18. 72. 0
Next subnet address = 172. 18. 80. 0/21
Broadcast address is 172. 18. 79. 255/21 of 172. 18. 72. 0/21 network.
Valid host range = 172. 18. 72. 1 to 172. 18. 79. 254

Example 5:

What valid host range is the IP address 172.23.144.133/24 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.255.0 (/24)
Valid subnets = 256 – 255 = 1, which means we have a block size of 1 in the third octet.
Count by 1 until reaching 144.
Subnets are 0, 1, 2, 3 etc.
Address 144 falls in the 144 subnet.
Subnet = 172. 23. 144. 0
Next subnet address = 172. 23. 145. 0/24
Broadcast address is 172. 23. 144. 255/24 of 172. 23. 144. 0/24 network.
Valid host range = 172. 23. 144. 1 to 172. 23. 144. 254

Example 6:

What valid host range is the IP address 172.25.155.112 255.255.255.0 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.255.0
Valid subnets = 256 – 255 = 1, which means we have a block size of 1 in the third octet.
Count by 1 until reaching 155.
Subnets are 0, 1, 2, 3 etc.
Address 155 falls in the 155 subnet.
Subnet = 172. 25. 155. 0
Next subnet address = 172. 25. 156. 0/24
Broadcast address is 172. 25. 155. 255/24 of 172. 25. 155. 0/24 network.
Valid host range = 172. 25. 155. 1 to 172. 25. 155. 254

Example 7:

What valid host range is the IP address 172.26.85.2/26 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.255.192
Valid subnets = 256 – 192 = 64, which means we have a block size of 64 in the forth octet.
Subnets are 0, 64, 128 etc.
Address 2 falls in the 0 subnet.
Subnet = 172. 26. 85. 0
Next subnet address = 172. 26. 85. 64/26 
Broadcast address is 172. 26. 85. 63/26 of 172. 26. 85. 0/26 network.
Valid host range = 172. 26. 85. 1 to 172. 26. 85. 62

Example 8:

What valid host range is the IP address 172.26.229.139/22 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.252.0
Valid subnets = 256 – 252 = 4, which means we have a block size of 4 in the third octet.
Count by 4 until reaching 229.
Subnets are 0, 4, 8, 12, … , 224, 228, 232 etc.
Address 229 falls in the 228 subnet.
Subnet = 172. 26. 228. 0
Next subnet address = 172. 26. 232. 0/22 
Broadcast address is 172. 26. 231. 255/22 of 172. 26. 228. 0/22 network.
Valid host range = 172. 26. 228. 1 to 172. 26. 231. 254

Example 9:

What valid host range is the IP address 172.26.237.115/21 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.248.0 (/21)
Valid subnets = 256 – 248 = 8, which means we have a block size of 8 in the third octet.
Count by 8 until reaching 237.
Subnets are 0, 8, 16, … , 224, 232, 240 etc.
Address 237 falls in the 232 subnet.
Subnet = 172. 26. 232. 0
Next subnet address = 172. 26. 240. 0/21 
Broadcast address is 172. 26. 239. 255/21 of 172. 26. 232. 0/21 network.
Valid host range = 172. 26. 232. 1 to 172. 26. 239. 254

Example 10:

What valid host range is the IP address 172.27.80.39 255.255.254.0 a part of?

Solution:

Class B addresses use a default mask of 255.255.0.0
Given subnet mask = 255.255.254.0 (/23)
Valid subnets = 256 – 254 = 2, which means we have a block size of 2 in the third octet.
Count by 2 until reaching 80.
Subnets are 0, 2, 4, … , 78, 80, 82 etc.
Address 80 falls in the 80 subnet.
Subnet = 172. 27. 80. 0
Next subnet address = 172. 27. 82. 0/23 
Broadcast address is 172. 27. 81. 255/23 of 172. 27. 80. 0/23 network.
Valid host range = 172. 27. 80. 1 to 172. 27. 81. 254

Class C

Example 11:

What valid host range is the IP address 192.168.70.38/30 a part of?

Solution:

Class C addresses use a default mask of 255.255.255.0
Given subnet mask = 255.255.255.252 (/30)
Valid subnets = 256 – 252 = 4, which means we have a block size of 4 in the forth octet.
Count by 4 until reaching 38.
Subnets are 0, 4, 8, .. , 36, 40 etc.
Address 38 falls in the 36 subnet.
Subnet = 192. 168. 70. 36
Next subnet address = 192. 168. 70. 40/30 
Broadcast address is 192. 168. 70. 39/30 of 192. 168. 70. 36/30 network.
Valid host range = 192. 168. 70. 37 to 192. 168. 70. 38

Example 12:

What valid host range is the IP address 192.168.166.57 255.255.255.192 a part of?

Solution:

Class C addresses use a default mask of 255.255.255.0
Given subnet mask = 255.255.255.192 (/26)
Valid subnets = 256 – 192 = 64, which means we have a block size of 64 in the forth octet.
Subnets are 0, 64, 128, 192 etc.
Address 57 falls in the 0 subnet.
Subnet = 192. 168. 166. 0
Next subnet address = 192. 168. 166. 64/26 
Broadcast address is 192. 168. 166. 63/26 of 192. 168. 166. 0/26 network.
Valid host range = 192. 168. 166. 1 to 192. 168. 166. 62

Exercise

Exercise 1:

What valid host range is the IP address 172.28.209.108/23 a part of?

Answer:

Valid host range = 172. 28. 208. 1 to 172. 28. 209. 254

Exercise 2:

What valid host range is the IP address 172.28.219.103/27 a part of?

Answer:

Valid host range = 172. 28. 219. 97 to 172. 28. 219. 126

Exercise 3:

What valid host range is the IP address 172.31.173.115/25 a part of?

Answer:

Valid host range = 172. 31. 173. 1 to 172. 31. 173. 254

Exercise 4:

What is the valid host range for the IP address 192.168.1.188 255.255.255.224 ?

Answer:

192. 168. 1. 161 - 190

Exercise 5:

What is the valid host range of the host ID 192.168.20.33 255.255.255.224 is a part of ?

Answer:

192. 168 . 20. 33 - 62

Exercise 6:

A host on your IP network has the IP address 208.20.208.85 and subnet mask 255.255.255.240.
What is the range of possible host addresses on this subnet?

Answer:

208. 20. 208 .81 To: 208. 20. 208. 94