@Override
        public String getName() { return "duo-enforce-hosts"; }
The optional property that contains a comma-separated list of IP addresses
or CIDRs for which the MFA requirement should be explicitly enforced. If
the Duo module is enabled and this property is specified, users that log
in from hosts that match the items in this list will have Duo MFA required,
and all users from hosts that do not match this list will be able to log
in without the MFA requirement. If this option is missing or empty and
the Duo module is installed, MFA will be enforced for all users.
extensions/guacamole-auth-duo/src/main/java/org/apache/guacamole/auth/duo/conf/ConfigurationService.java