Troubleshooting AWS Client VPN: Unable to resolve the Client VPN endpoint DNS name - AWS Client VPN

Troubleshooting AWS Client VPN: Unable to resolve the Client VPN endpoint DNS name

Problem

I am unable to resolve the Client VPN endpoint's DNS name.

Cause

The Client VPN endpoint configuration file includes a parameter called remote-random-hostname. This parameter forces the client to prepend a random string to the DNS name to prevent DNS caching. Some clients do not recognize this parameter and therefore, they do not prepend the required random string to the DNS name.

Solution

Open the Client VPN endpoint configuration file using your preferred text editor. Locate the line that specifies the Client VPN endpoint DNS name, and prepend a random string to it so that the format is random_string.displayed_DNS_name. For example:

  • Original DNS name: cvpn-endpoint-0102bc4c2eEXAMPLE.clientvpn.us-west-2.amazonaws.com

  • Modified DNS name: asdfa.cvpn-endpoint-0102bc4c2eEXAMPLE.clientvpn.us-west-2.amazonaws.com