title: Can't ping AWS RDS instance after allowing ICMP
body: <p>I'm trying to ping my newly set up AWS RDS instance, but I am unable to do so (four "Request timed out" errors).</p>
  
  <p>I added a rule in my EC2 security group for the instance, allowing all ICMP but it still does not work.</p>
  
  <p>I am new to this, so apologies if I'm missing something obvious. Thanks!</p>