If you check the properties of a Site in IIS, you can find that IP Address listing has an (All Unassigned) tag to it. If you go to the drop down list besides it, it will list only one IP (the default primaryIP) inspite of the fact that your server may be multihomed. This forces us to leave each Site to (All Unassigned) Tag inspite of the fact that we may want to assign different IP's to each.

Solution

Open the "hosts" file in the following location and add the mappings of all the IP's to the servers name. Initially it will have only one mapping, that of the Primary IP to server name.

%systemroot%\system32\drivers\etc

Add the new entries as follows

IP.IP.IP.IP<press tab here>SERVER_NAME

Caution
1. Server_Name will be same for all IP's
2. The HOSTS file has no extension.
3. It is not necessary to restart IIS.
4. If the listing still doesnt show up use the following on command line
nbtstat -R

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