I have a web server with a domain on it that has a dedicated IP address. I need the shared IP address for the server to show up during a reverse DNS lookup.
The dedicated IP has an A record which works and looks like this,
example.com 14400 A 123.45.67.890 // Dedicated IP
The shared IP shows up for all other sites on the server except for this one that has the dedicated IP. I added an A record for the shared IP which does not show up when I reverse DNS lookup,
sharedip.example.com 14400 A 098.76.54.321 // Shared IP
I can't tell if I am adding the Shared IP correctly or I should be doing this in a different way.
Question
To attach the Shared IP to the domain which already has a dedicated IP is the proper way to use an A record with a sub domain
sharedip.example.com 14400 A 098.76.54.321
considering the dedicated is attached to the domain without a sub domain as show above?
example.com 14400 A 123.45.67.890 // Dedicated IP