Help on finding the network address for given IP address and subnet mask.
To calculate network address from a given IP address and subnet mask, follow the the steps below.| Steps |
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| 1. For any octet if the subnet mask value is 255, copy the IP octet; If the subnet mask is 0, write 0 into the network address for that octet. |
| 2. For any octet, if the subnet mask is neither 0 nor 255: (a) Calculate the jump = 256-subnet mask. (b) Check the integer multiples of jump and find THE largest integer multiple of jump that is <= IP value on that octet. Copy that specific integer multiple into the network address for that octet. |
| Example1:IP: 130.143.214.6 and Subnet mask: 255.255.0.0. After you finish step 1, The network address is 130.143.0.0. |
| Example2:IP: 156.103.214.110 and Subnet mask: 255.255.240.0 After finishing step 1, you have 156.103._____.0. After finishing step 2.a), jump=16 for the 3rd octet At step 2. b) the multiples of jump are 0, 16, 32, 48.......the multiple of jump smaller than or equal to the ip on 3rd octet =112. The network address becomes 156.103.208.0 |
| Example3:IP: 52.15.196.117 and Subnet mask: 255.255.255.192. After finishing step 1, you have 52.15.196.____. After finishing step 2.a), jump=64 for the 4th octet At step 2. b) the multiples of jump are 0, 64, 128, 192, 256...and the multiple of jump smaller than or equal the ip on 4th octet =64. The network address becomes 52.15.196.64 |