|I take it you are hosting your own web site. If this is the case then this is expected behaviour. Most routers will not allow you to access a website from within the LAN via a public IP address, you have to use the local address of the web site.|
The only router I know of that will allow you to do what you are trying is a Belkin. No amount of URL forwarding is going to solve the problem as it is a characteristic of the router.