AWS DNS Across Multiple VPCs

I am trying to understand how to make DNS work with AWS RDS and tailscale.

Some context before I get into the problem:

  • Two AWS Accounts (Dev and Prod)
  • Each AWS Account has its own RDS Instance and VPC
  • Each AWS Account has its own CIDR Range
  • All the AWS RDS are hosted in the same region so they have the same DNS entry (ie us-east-1.compute.internal)

I am looking into Step 3 of Accessing AWS RDS privately.

How do people handle the same DNS entry with nonoverlapping CIDR ranges on different VPCs?

Some people recommended shutting off one subnet router and turning on the other. I would think I don’t have to do this because I do not have conflicting CIDR ranges.