mojoPortal only cares about the host names, but you can use whatever ip addresses you like for each host name.

You just need to add host headers in IIS for each ip address assigned to the IIS Web Site. You can assign multiple ip addresses each with different host names to a single IIS Web site, or you could create multiple IIS Web sites that all point to the same file system location where mojoportal is installed.

If all the sites use the same ip then it is slightly easier because you don't have to set the host headers in IIS, but with different ip addresses you will need to add the host headers associated with each ip address.

Hope it helps,

Joe