ORA-55321: network already exists
Cause: Attempt to create the network failed because the network already existed.
Action: If necessary, drop the network before trying to recreate the network.
ORA-55321是由于请求的网络已经存在造成的。这是由于该网络或子网已经通过DBMS_NETWORK_ACL_ADMIN.CREATE_NETWORK_ACL被创建。
ORA-55321: 请求的网络已经存在
当使用 DBMS_NETWORK_ACL_ADMIN.CREATE_NETWORK_ACL 尝试创建已经存在的网络时，会发生此错误。
1.尝试查找网络是否存在：
SELECT * FROM DBA_NETWORK_ACLS
WHERE HOST = :host_name
AND LOWER_PORT
AND UPPER_PORT >= :port_num
2.若已存在，可删除此网络：
BEGIN
DBMS_NETWORK_ACL_ADMIN.DELETE_NETWORK_ACL (
acl => :acl_name,
host => :host_name,
low_port => :port_num,
high_port => :port_num);
END;
3.然后重新创建网络：
BEGIN
DBMS_NETWORK_ACL_ADMIN.CREATE_NETWORK_ACL (
acl => :acl_name,
description => :description,
host => :host_name,
lower_port => :port_num,
upper_port => :port_num);
END;