Restrict access
To enhance security you can limit the locations (IP Addresses) where users can login to the system. You can set this per group:

Allowed groups
Warning
You can easily lock everybody out from the system with this feature. I recommend that you add group “Admins” with pattern “*” first so that Admins can always login. When you’re sure everything is setup correctly you can remove that rule.
Rules
Login is allowed when:
There are no rules defined for any group you are a member of.
One of the rules of groups you are a member of matches your IP address
Each rule has a group and a pattern for IP addresses. You can use “*” to match any part of an IP address and ‘?’ to match a single character.
Some examples:
“*” will match any IP address
“192.168.1.?” will match 192.168.1.1 till 192.168.1.9.
“192.168.1.* will match 192.168.1 till 192.168.1.255