Question : DNS Resolver for an FTP

I want to setup a third party FTP directory for a customer
But I wanted to make sure there is no way for their customer to see that we own the FTP
Server, I did a DNS lookup on our external IP address and I only see our service providers information but we do have a domain name that points to this address as well. Do you think there is a way to find out we own the server if we only give them the IP address.

Thanks

Answer : DNS Resolver for an FTP

And of course if you use other web services on the same ip address they might find out about you from those other services. Like Web Services, Remote Desktop Connection services and so on...