title: Single AWS WAF on multiple ALB
body: <p>My application architecture's allowed traffic flow is as below in AWS.</p>
  
  <p>CompanyInternalSubnets(IS)=>ALB with WAF=>EC2</p>
  
  <p>ALB has security groups which allows only traffic from IS. ALB has WAF which has rules to allow traffic only from IS. EC2 has security group which allows only traffic from ALB's SG.</p>
  
  <p>I want to create multiple replica of same application in AWS. I will create sperate EC2 and ALB. but can i use same WAF and attach it to second ALB or do i need to use separate WAF fur each replica? what is the best practice?</p>
  
  <p>Thanks</p>