Define a named access control list. An ACL is a
list of network addresses in CIDR notation, one address per line,
terminated with an End directive on a line by itself. E.g.:
ACL "secure" "192.0.2.0/26" "203.0.113.0/24" End
The Include directive is allowed within the ACL section.
Named ACLs can be used in Service definitions to limit access
to services from certain IP addresses only. See ACL, for a
detailed discussion of this.