title: How to convert ipv6 to binary and abbreviate it?
body: <p>Example:user will enter <code>ffff:0000:ffff:ffff</code> and out put must be like this:</p>
  
  <pre><code>1111111111111111:0000000000000000:1111111111111111:1111111111111111
  </code></pre>
  
  <p>I need it in c#
   abbreviate example: </p>
  
  <pre><code>1111111111111111:::000000000000:1111111111111111:1111111111111111
  </code></pre>