>>>Hi,
>>>
>>>I have installed an ASP.NET application on the customer web server (new virtual server). The application is using form authentication. Now I need to tell them to make the pages of the application available/accessible from any place on the Internet. What specifically would they (the IT of the customer) have to do to make it happen?
>>
>>In essence:
>>(a) Make sure the IP address of the web server is accessible on the Internet.
>>(b) Tell potential users the address.
>>
>>But I don't think you've asked the right question :-}
>
>Should my question have been "how to make the IP address of the web server accessible on the Internet"? How do you do it? Thank you.

Probably, the company has a firewall that restricts incoming traffic originating from the public Internet. The firewall will need to be reconfigured to allow incoming Web traffic to your new site.

The company's external (public) IP address (e.g. aaa.bbb.ccc.ddd) should ideally be static. They may need to upgrade their Internet service if it is not.

Hopefully your Web server has a static internal (LAN) IP address, say 192.168.xxx.yyy. For standard Web HTTP traffic the firewall will need to be reconfigured to forward incoming traffic on TCP port 80 to 192.168.xxx.yyy. If your server makes use of SSL (HTTPS), port 443 will need to be forwarded as well.

If the company does not already have a Web server, for users' convenience they'll probably want to reconfigure their domain's DNS so that www.somedomain.com resolves to their external (public) IP address aaa.bbb.ccc.ddd. This will involve logging in to their domain registrar with a user name and password which hopefully they have retained somewhere.

If they don't update their DNS settings, users will have to visit their site via http://aaa.bbb.ccc.ddd which is do-able, but not ideal.

Finally, before you go public with your server/site, be sure it's up-to-date with patches etc. and that it's locked down to reduce the chance of compromise. Every single public Web server is probed for vulnerabilities by bad guys multiple times per day. Have recent, good (preferably image) backups of the server and be prepared to blow it away and rebuild from an image in the event of compromise.

If the company is large enough to have their own IT support staff/network admin, s/he should be able to do all of the above for you. If not, hire someone who knows what they're doing.