尝试访问删除的 oracle db 19.3 时遇到一些问题。VM（CentOS 7）位于 GCP Cloud 内部，我可以在其他端口（22）上对其进行 ping 操作，但我无法使用 sqldeveloper 连接到数据库，甚至无法使用 telnet ping 端口 1521。
防火墙已禁用并且 lsnrctl 状态已启动，但我有点担心输出：
LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 30-MAR-2023 18:13:07
Copyright (c) 1991, 2019, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date 30-MAR-2023 16:54:43
Uptime 0 days 1 hr. 18 min. 24 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /oracle/product/19.3/db_home/network/admin/listener.ora
Listener Log File /oracle/diag/tnslsnr/oracle-19c/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle-19c.c.enhanced-tuner-382015.internal)(PORT=1521)))
Services Summary...
Service "CDB" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
Service "CDBXDB" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
Service "f810a6809fc55a12e0530300840a2cc0" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
Service "f810a75fde6b5b22e0530300840a8ce6" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
Service "orcl" has 1 instance(s).
Instance "orcl", status UNKNOWN, has 1 handler(s) for this service...
Service "pdb1" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
Service "pdb2" has 1 instance(s).
Instance "CDB", status READY, has 1 handler(s) for this service...
The command completed successfully
以下是 netstat -tlpn | grep 1521 的输出：
tcp6 0 0 :::1521 :::* LISTEN 1298/tnslsnr
此外，这 3 个文件 *.ora 文件不是从一开始就添加到 $ORACLE_HOME/network/admin/ 中的，因此我从“samples/”中添加了它们，但我认为它们中的大多数都是空的/被注释掉了。
我也尝试重新启用firewalld服务并启动它，为端口添加防火墙例外，并在GCP中添加防火墙例外，但仍然无法实现。
请告诉我我还遗漏了什么。谢谢！