Well I assume it's simple but I can't quite see how to sort it out.
I'm running Slackware 11 on my home machine and, on the home network, its IP address is 192.168.1.1, it's running apache 1.3.37 (the Slackware 11 default).
I have set up my router/firewall so that HTTP requests are sent to 192.168.1.1. At just-the-name I have the domain isbd.ltd.uk set up so that HTTP requests are routed to my static IP address at my ISP.
So far, so good, if you go to http://www.isbd.ltd.uk/ up pops the default apache index.html page to indicate that it's all working.
However, if I go to http://www.isbd.ltd.uk/~chris then instead of bringing up the index.html that I have in the public_html directory in my home directory on the Slackware system I get an error:-
Firefox can't find the server at server.isbd.ltd.uk.
... and Firefox is looking for http://server.isbd.ltd.uk/~chris/ which of course doesn't work because server.isbd.ltd.uk doesn't exist in the outside world.
How do I get my Slackware machine to look like isbd.ltd.uk when seen from the outside world but give it the name server and/or server.isbd.ltd.uk internally to my home network?