Thursday, October 27, 2022

[SOLVED] EC2 instance in IPv6-only subnet has no public DNS

Issue

The VPC for my instance has DNS hostnames enabled, but the instance does not have a public DNS hostname. I need to test hostname resolution in IPv6-only environments, but instances do not seem to be assigned a public DNS hostname.

I created an EC2 instance with ipv6-only. It was assigned an ipv6 address, but no hostname. When I do a DNS-reverse lookup, the lookup is unsuccessful.

And what is the use for private DNS hostnames? Can they be reached/pinged from other instances or machines?


Solution

You can enable Resource-Based DNS hostnames for IPv6-only EC2 instances. This will use the instance ID for the hostname, instead of the IP address.

Note however that this is only for private DNS hostnames. Public DNS hostnames are not supported for IPv6-only EC2 instances.



Answered By - Mark B
Answer Checked By - David Goodson (WPSolving Volunteer)