Hi Robert
I've tried your suggestions, and can report the following:
1) OK
2) I replaced localhost/dotnetnuke in the PortalAlias table with www.domain.com:81
3) I didn't restart IIS as I didn't want to stop other websites but I added a blank line to the start of web.config and saved it which I hope does the same thing?
I'm sorry to report there is no difference from outside the firewall, I'm seeing a "Failed to connect" page in Firefox "The connection was refused when attempting to contact www.marketingunity.com:81."
My previous attempts were with a new portal that I'd added, I'd left the first/default portal alone. This time I removed all portal aliases from the 2nd portal and changed the localhost/.. as recommended, not only does that not work externally but now on the server I am getting "Server Error in '/dotnetnuke' Application." and "
Object reference not set to an instance of an object. "
I think I'll have to go back to localhost/dotnetnuke in the portalalias table to get into dnn on the server again?
Many thanks for bearing with me, I'm sure it's my lack of understanding that has made my do something wrong during setup, or something.
John