title: Ping not working?
body: <p>I read from a book, says that two computer A and B:</p>
  
  <p>A: 192.168.26.129/24 gateway 192.168.26.2</p>
  
  <p>B: 192.168.26.3/27 gateway 192.168.26.2</p>
  
  <p>The book say that if B ping A, it can works.</p>
  
  <p>i.   So I test it on cisco packet tracker, and it's not working?</p>
  
  <p>ii.   But after I change the B to 192.168.26.3/24, and it can work fine, I know that.</p>
  
  <p>iii.   Then I test change B to 192.168.26.3/24, it is still work.</p>
  
  <p>What is the difference between step (i) with setp (iii)?</p>
  
  <p>I know it must relative to arp? someone can tell the detial? or did I do something wrong?</p>