Subdomains issue - Trying to limit to specific but all work
We are trying to limit access to a specific sub domain by specifically whitelisting it via FQDN, as we might want to allow other sub domains at a later date. However all sub domains are being allowed through. For example:
However all sub domains such as:
All sub domains share the same IP address, and I have been advised that this might be the problem. Is this normal behavior? This is an initial sanity check to make sure I am not missing a fundamental.