A netmask is a 32-bit mask used to divide an IP address into subnets and specify the networks available hosts. In a netmask, two bits are always automatically assigned. For example, in, "0" is the assigned network address; and in, "255" is the assigned broadcast address. The 0 and 255 are always assigned and cannot be used.


CIDR to Netmask

This tool converts CIDR to netmask.


Netmask to CIDR

This tool converts netmask to CIDR.


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CIDR calculator
CIDR Calculator

Add this to your web site by copy the following HTML code and place it in your web page.


<form action="" method="post">
<p style="background:#fff;border:1px solid #99A8AE;width:180px;padding:5px 5px 5px 5px;font-size:11px;font-family:'Trebuchet MS',Arial,Sans-serif;">
	<a href="" target="_blank"><img src="" alt="CIDR calculator" border="0" width="120" height="12" /></a><br />
	<b>CIDR Calculator</b><br /><br />
	<label>CIDR</label> <input type="text" name="cidr" value="" style="border:solid 1px #C0C0C0;font-size:9px;width:110px;" /><br />
	<input type="submit" value="Calculate" style="width:100px;font-size:10px;margin-top:3px;padding:2px 3px;color:#FFF;background:#8EB50C;border-width:1px;border-style:solid;">

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