SHaredIP issue and DNS

I have an issue with SharedIP and DNS
here is my set up

Nat router ip 196.213.x.x - external IP
ISPConfig server 192.168.0.250 - internal IP

If I setup a new site and configure it to the IP 192.168.0.250 the site works but this will then present a problem for the DNS records as then all DNS records point to the internal address.

I a change the site to 196.213.x.x the external IP DNS works for extrenal users but I get the SHAREDIP page ?

Can anyone help ?

this happens on existing and new sites

 

Thanks Till,

So am I right in say when we create a new site we allocate it the internal ip and tick the create DNS check box, then I need to go into DNS manager and change the ip for that site to the external IP, or is there a way to set it that by default is use the internal IP for the sites but writes the external IP in the DNS manager ?

 

Yes, that's right.