title: AWS best practice: shall I have a NAT gateway in each AZ?
body: <p>Since NAT gateway only have redundancy within a single AZ, if I want to have a public/private pair of subnets in every AZ for the purpose of multi-AZ redundancy, I should have a NAT gateway in every AZ, shouldn't I? </p>
  
  <p>Otherwise, if I have only one NAT, if the AZ goes down, all the subnets in all AZs go down with it, thus defeating the purpose of this multi-AZ deployment.</p>
  
  <p>Am I right or wrong?</p>