title: IP addressing - Network prefix - Help understanding
body: <p>I am currently studying for an IT exam, and looking into IP addressing. I have thus come across the following question: </p>
  
  <p><strong>For a given class C network 194.1.2.3, what is the network prefix?</strong></p>
  
  <p>I know this is a fairly simple, theoretical question, but I need to understand why. So far, I have the following working: </p>
  
  <p>IPv4 applies dotted-decimal notation to divide the 32-bit address into four 8-bit fields (for readability).</p>
  
  <p>Furthermore, the IP address space (not sure if right term) is divided into three classes (A, B, and C) to support networks of different sizes (classful addressing). </p>
  
  <pre><code>XXXX . XXXX . XXXX. XXXX
  </code></pre>
  
  <p>I also know the following: </p>
  
  <pre><code>Address Class A    A(/8 prefixes)
  Address Class B    B(/16 prefixes)
  Address Class C    C(/24 prefixes)
  </code></pre>
  
  <p>I have thus concluded that <strong>194.1.2</strong> constitutes the network prefix of the given class C network, seeing that these make up the first 24 bytes. </p>
  
  <p>Is this correct; and if so: Would the prefix for class A and class B networks be 194 and 194.2 respectively?</p>
  
  <p>Thanks in advance!</p>