How do I know if the URL I've requested is DNSSEC-aware?
Browsers are not currently set up to identify DNSSEC. They don't give you visual feedback for DNSSEC-secured sites like they do when a site is secured by an SSL — that is, the padlock icon.
If there's a verification problem with a DNSSEC-aware URL, however, you receive a message indicating that the site does not exist — a 404 Not Found error.