A very simple example of creating an ACL for a principal and a host:
Creating the ACLS (qith the associated principal) itself.
exec dbms_network_acl_admin.create_acl( acl=>'print_permissions.xml',
description=>'Gebruikt voor Print functionaliteit',
principal=>'APEX_230100',
is_grant=>TRUE,
privilege=>'connect');
Associating a host to the ACL:
exec dbms_network_acl_admin.assign_acl( acl=>'print_permissions.xml',
host=>'machine-name.domain.domain',
lower_port=>8010, upper_port=>8010);
This is a starting point. You can go from here …
(for security reasons I altered some fields)