Editing Subnet (section)

===Determining the network prefix===
An IPv4 subnet mask consists of 32 bits; it is a sequence of ones (''1'') followed by a block of zeros (''0''). The ones indicate bits in the address used for the network prefix and the trailing block of zeros designates that part as being the host identifier.

The following example shows the separation of the network prefix and the host identifier from an address ({{IPaddr|192.0.2.130}}) and its associated {{IPaddr||24}} subnet mask ({{IPaddr|255.255.255.0}}). The operation is visualized in a table using binary address formats.
{| class="wikitable" style="margin:left;"
!
! Binary form
! Dot-decimal notation
|-
| IP address
| <code>11000000.00000000.00000010.10000010</code>
| 192.0.2.130
|-
| Subnet mask
| <code>11111111.11111111.11111111.00000000</code>
| 255.255.255.0
|-
| Network prefix
| <code>11000000.00000000.00000010.00000000</code>
| 192.0.2.0
|-
| Host identifier
| <code>00000000.00000000.00000000.10000010</code>
| 0.0.0.130
|}
The result of the [[bitwise AND]] operation of IP address and the subnet mask is the network prefix {{IPaddr|192.0.2.0}}. The host part, which is {{IPaddr|130}}, is derived by the bitwise AND operation of the address and the [[ones' complement]] of the subnet mask.