The web.config
file in the root of your web site is not the only file where configuration is/can be stored in IIS.
Further web.config file can exist in sub-folders of your site.
Many settings are by default not supposed to be saved in the site's web.config and therefor be edited by a normal user. These settings are stored in a central file which also has the configuration for the server level.
the file is at:
C:\Windows\System32\inetsrv\Config\ApplicationHost.config
IP security rules are by default stored in ApplicationHost.config
If you open IIS Manager and select the server level, and then under Management click on the Feature Delegation
icon you can see a list of features.
IP Address and Domain Restrictions
are listed as Read Only
which means they can only bo stored in the ApplicationHost.config
file. If you change this to Read/Write
they may be stored in your site's web.config
file as well.
If you are going to use IIS a lot, make yourself familiar with the hierarchical configuration system in IIS.