Click on IP Access Control on the module's main page to bring up the access control form.

Select Only allow from listed addresses and enter a list of hostnames, IP addresses, and networks into the adjacent text box. Networks should be entered with a netmask like 192.168.1.0/255.255.255.0. You can allow access from an entire DNS domain by entering something like *.example.com, but be aware that that is not totally secure because an attacker can fake reverse DNS results.

Normally Webmin will resolve any hostnames that you enter only once when it first starts up. To change this, check the Resolve hostnames on every request box and it will convert hostnames to IP addresses for comparison for every request. This can be useful if the system you are running a browser on is frequently changing IP addresses but is able to update a DNS record to match. This can happen on a network using DHCP or if you are connected to an ISP that dynamically assigns addresses.

To have Webmin check the TCP-wrappers configuration files /etc/hosts.allow and /etc/hosts.deny as well when deciding whether to allow a client, turn on the Also check TCP-wrappers hosts.allow and hosts.deny files option. The service name to use when editing those files is webmin.

Hit the Save button to activate the new client address restrictions.