Scenario

I’ve created an AWS Route53 Private Hosted Zone, and set a type A DNS record in it that is an alias for an internal Application Load Balancer that is in the same VPC that is associated with the Private Hosted Zone. The VPC has DNS Hostnames and DNS Resolution enabled. The VPC has private and public subnets, with NAT gateways in the public subnets for egress. While shelled into EC2 that is one of the private subnets, I have confirmed that I can route directly to the internal Application Load Balancer at its AWS-given DNS name (the long “blahblahblahblah.us-east-1.elb.amazonaws.com” DNS record that it gets automatically). However when I make requests against the friendly DNS record that I set in the private hosted zone, I get a “Could not resolve host” message back. I’ve also confirmed that the DNS record has sync’d, and given it 24hrs just to be sure. The DNS servers for the VPC are the default AWS ones, I’ve not changed them.

Question

Given the above, and that I’ve already checked the two things that the docs and forums constantly call out (DNS Hostnames and DNS Resolution enabled in the VPC)… What else could be misconfigured? Are there additional debugging steps that anyone can think to take? Are there other configurations that must be in place, in order for a private hosted zone’s DNS record to be resolvable from inside the VPC?