HTTP 301 redirect http://.example.com to http://www.example.com

Question

One of my customers has recently had their site reviewed against best practice for security, SEO, end-user experience etc, and interestingly one of the points highlighted in the final report was that they stated the customer should:

"Put a permanent (HTTP 301) redirect to http://www.example.com on http://.example.com".

At present there are A records for www and @ with a 301 redirect when the requested host name is missing the www prefix (I've checked this is working correctly), however there are also subdomains such as webmail.example.com and imap.example.com etc.

Without using an asterix (*) A record to catch-all, how can I address this point?

I've always thought the hostname part could never start or end with a full stop but that they were used only as separators, and having checked, IETF RFC 1035 states, p8, s2.3.1, "Preferred Name Syntax":

The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen.

And while the section title uses the word Preferred the paragraph at s2.3 prior to the above paragraph makes it clear that this syntax is mandatory for Internet-connected systems.

Does anyone believe this domain beginning with a dot but no subdomain could be considered valid under any circumstances? If I try to connect via HTTP I get the error:

Domain name lookup failed: http://.example.com/

(Note: real domain name substituted for example.com throughout this question)

Answer 1

It turns out this was indeed a bug in their system where the introduction of .uk domains a year ago as a country-code top level domain (ccTLD) and not just as a second-level domain (e.g. .co.uk, .org.uk, .ac.uk etc.), had not yet been catered for in their system.