Secure NNTP Access by IP Address, Subnet, or Domain
To further enhance security, you can selectively include or exclude single computers, subnets, and entire domains from accessing an NNTP virtual server. By default, all computers have access until you add them to a list of restricted computers. You can restrict access to the NNTP virtual server by either listing individual computers that use newsgroups, or by specifying a group of computers that do not use newsgroups.
To secure access by IP address, subnet, or domain: