title: How many Number of Networks for class B and class C?
body: <p>In the tutorial on ip4 adress classes:<br>
  <a href="http://www.tutorialspoint.com/ipv4/ipv4_address_classes.htm" rel="nofollow noreferrer">http://www.tutorialspoint.com/ipv4/ipv4_address_classes.htm</a>   </p>
  
  <p>Class B has 16384 <code>(2**14)</code> Network addresses and 65534 <code>(2**16-2)</code> Host addresses.<br>
  Class C gives 2097152 <code>(2**21)</code>Network addresses and 254 <code>(2**8-2)</code> Host addresses.
  <a href="https://i.stack.imgur.com/jiciT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jiciT.png" alt="enter image description here"></a></p>
  
  <p>In the tutorial on ip4 adress classes:<br>
  <code>http://www.vlsm-calc.net/ipclasses.php</code>      </p>
  
  <p>Class B has <code>163842(2**14-2)</code>Network addresses and 65534 <code>(2**16-2)</code> Host addresses.              </p>
  
  <p>Class C gives 20971520<code>(2**21-2)</code> Network addresses and 254 <code>(2**8-2)</code> Host addresses.<br>
  <a href="https://i.stack.imgur.com/906Ze.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/906Ze.png" alt="enter image description here"></a>
  Both of them for class A ,the number of networks is 126 <code>(2**7 – 2)</code>.<br>
  Which number of networks on class B and class C is correct?<br>
  For class B , the number of networks  is    <code>(2**14-2)</code>  or <code>(2**14)</code>?<br>
  For class C , the number of networks  is    <code>(2**21-2)</code>  or <code>(2**21)</code>?</p>