On a Windows 2003 with Plesk, even though IIS hosts the web sites, Plesk must have manipulate the http header so web request will go to a designated web site according to its domain name.

Unless a web site has an exclusive IP or a shared IP has chosen this web as default, Web request to a IP site won't find the target site but hit Plesk "default" page.

I have a requirement to allow web site assigned to multiple IP address, then web request to these IP address with different domain names (one for each IP) all hit this web site. The only way I can achieve this is to configure IIS web site for "all unassigned IP" instead of a given IP (I would have to change it on IIS). Since in this case, the web site is not tight to any "exclusive" or "shared" IP, with Plesk in place to translate incoming web traffice, web request has to go through Plesk to resolve domain name before it can find the target site, thus in this case will not find the target site so to speak.

I like to use Plesk to add domain/client/IP and manage everything, but is it possbile to just turn off this one function that has something to do with translating incoming web traffice on behalf of IIS and resolving domain name?

You can manually modify the DNS in Plesk in order for the domain names to resolve properly.

Do you mean the "DNS" icon in Plesk once select "server" from the left?

In there, it allows to add "xxx". A record. What is this means? it's grey out, cannot be modified. How is it going to help resolve the domain name in incoming traffic?

I'd appreciate if you could elaborate a bit more.

I believe that what I am doing is pretty close to what you are asking. I found the answer on the ev1 forums myself.

C:Program FilesSWsoftPleskdnsvar is where all of the records are kept. You will have at least one file that ends "in-addr.arpa". On my machine, one is 61.15.67.in-addr.arpa. If you open these files in notepad or wordpad, you will notice a list of domains and the last part of your ips. These files will need to be edited with the other domains.

Also in the var directory, there are files that correspond to the different domain names, in my case sthsband.org is one of them. You can copy these files and edit and rename them so that the information matches your domains. Then you can manually add these domains onto the correct site in IIS and things will work fine. I also have sthsband.com, .net and .us, but they are all the same site. So in the var directory are files named sthsband .com .net and .us, and I've simply added those to the sthsband.org site in IIS and the site loads for any of those domains.