Firstly, many thanks for your speedy reply on my last enquiry. I have since registered my domain (fellview.net) and this forwards ok. However, I have also registered a subdomain (library.fellview.net) but I cannot get my server to redirect to the correct website. This is obviously something wrong with the setting on the Ubuntu 14.04 server. Directing fellview.net to an opened port on the router works fine, but not the subdomain. Any help that you can give on how to configure the Ubuntu server would be greatly appreciated. Many thanks. Dave Bailey

Are you using Apache to host your website? If so, you can setup host headers for each domain name. Below is a link to examples on setting up host headers:

https://httpd.apache.org/docs/current/vhosts/examples.html

When it comes to setting up port forwarding in the router, you can simply forward any traffic for a given port to the port on which the website is hosted without mentioning the domain name or sub domain name. Once the traffic reaches Apache, it should detect the domain name or sub domain name based on virtual host and display the website accordingly.

Many thanks once again, problem solved!