host name resolution in dba_network_acls

When you create an ACL with:

BEGIN  DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE  (  host => '',  lower_port => 10000,  upper_port => 65535,  ace => xs$  ace_type(privilege_list => xs$  name_list('jdwp'),  principal_name => 'myusername',  principal_type => xs_acl.ptype_db)  ); END; / 

and then a client tells Oracle to connect to a numeric ip address will Oracle use name resolution to match the host name with the ip address and if so, in which direction? Will Oracle try to make a reverse lookup for the ip address and compare the host names or will it make a domain name lookup and compare the ip addresses?