I have modified by Web.config to add the following
<add ipAddress="XXX.XX.XX.XX" allowed="true"/>
And i was able to restrict the access to only one IP.
After this i modified again and added two more IP's to the list.
But the other two IP's are not able to access the website.
I can confirm that the changes are made to proper web.config file. Restarted IIS 3-4 times from Command prompt. Also stop and start in IIS was done.
Still unable to see my changes.
Kindly help and suggest.