Is it possible to use a static private DNS name to route within VPC to correct instance under ELB

Question

Hi
I am a bit rusty on AWS (been using *another cloud provider* for years) so please excuse any confused terminology.
We are using ELB in front of a number of ec2 instances, and we want to make calls between them, ideally by name rather than IP, and without traffic going outside our VPC. Because our IPs are dynamic and also the DNS names relate to the IPs, if we put the private DNS name in our config we risk having to change it if we reboot anything.

Is there a concept of somehow allocating a fixed private dns name (e.g. widget.somename.private) which will always resolve to the correct instance of widget within the VPC and regardless of IP address changing? Or is there a way of changing our setup to achieve this?

Thanks

Accepted Answer

Is there a reason for the private IPs being dynamic? If not, you could assign them [fixed private IPs](https://repost.aws/knowledge-center/custom-private-primary-address-ec2) and resolve them via DNS using a [Route 53 private hosted zone](https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/hosted-zones-private.html) assigned to your VPC. This requires `enableDnsHostnames` and `enableDnsSupport` settings enabled in your VPC.

Is it possible to use a static private DNS name to route within VPC to correct instance under ELB

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