iis 7 - IP-restrictions on one part of a website's bindings?

Quite doable, you can even do sub-folder level IP restrictions in IIS-7. You have to install the feature that allows this ("IP and Domain Restrictions"). It will show up in the IIS-7 view under the IIS section and will be called "IP and Domain Restrictions".

Edit: IIS7 doesn't allow what you want. Bound addresses and hostnames are properties of sites, and a site has a monolithic settings base. In order to do what you need, you need to create a new site and apply different restrictions. You can do this a couple of ways.

• (supported) Completely duplicate the site directory structure in the other location.
• (probably not supported) Use 'mklink' to create a symlink to the first site's directories. You may have issues with competing web.config files, though.