<h1>Network ID</h1>
<ul>
<li>Calculated by the number of 1 bits are in a <a href="/second-brain/subnet-mask">subnet mask</a>
<ul>
<li>Example:
<ul>
<li><a href="/second-brain/ip-address">IP address</a>: <code>192.168.123.132</code>
<ul>
<li>Binary: <code>11000000.10101000.01111011.1000010</code></li>
</ul>
</li>
<li>Subnet mask: <code>255.255.255.0</code>
<ul>
<li>Binary: <code>11111111.111111111.111111111.00000000</code></li>
</ul>
</li>
<li>Network ID: <code>192.168.123.0</code></li>
</ul>
</li>
</ul>
</li>
</ul>
<h2>Logical ANDing to Calculate a Network ID</h2>
<ul>
<li>Computers combine the bits of a host's <a href="/second-brain/ip-address">IP address</a> and <a href="/second-brain/subnet-mask">subnet mask</a> to calculate the network ID</li>
</ul>
<table>
<thead>
<tr>
<th></th>
<th></th>
<th>First Octet</th>
<th>Second Octet</th>
<th>Third Octet</th>
<th>Fourth Octet</th>
<th></th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td><a href="/second-brain/ip-address">IP Address</a></td>
<td><code>11000000</code></td>
<td><code>00100010</code></td>
<td><code>01011001</code></td>
<td><code>01111111</code></td>
<td><code>192.34.89.127</code></td>
</tr>
<tr>
<td>AND</td>
<td><a href="/second-brain/subnet-mask">Subnet Mask</a></td>
<td><code>11111111</code></td>
<td><code>11111111</code></td>
<td><code>11111111</code></td>
<td><code>00000000</code></td>
<td><code>255.255.255.0</code></td>
</tr>
<tr>
<td>EQUALS</td>
<td>Network ID</td>
<td><code>11000000</code></td>
<td><code>00100010</code></td>
<td><code>01011001</code></td>
<td><code>00000000</code></td>
<td><code>192.34.89.0</code></td>
</tr>
</tbody>
</table>
<p><a href="/second-brain/networking">Networking</a> <a href="/second-brain/subnetting">Subnetting</a> <a href="/second-brain/ip-address">IP Address</a></p>

		First Octet	Second Octet	Third Octet	Fourth Octet
	IP Address	`11000000`	`00100010`	`01011001`	`01111111`	`192.34.89.127`
AND	Subnet Mask	`11111111`	`11111111`	`11111111`	`00000000`	`255.255.255.0`
EQUALS	Network ID	`11000000`	`00100010`	`01011001`	`00000000`	`192.34.89.0`