Score:0

oracle19c - Port 1521 open on remote VM and visible in netstat, but cannot ping with telnet

fj flag

I am running into some issues while trying to access a remove oracle db 19.3. The VM (CentOS 7) is located inside GCP Cloud and I can ping it on other ports (22), but i cannot connect to the database using sqldeveloper or even ping port 1521 with telnet.

The firewall is disabled and the lsnrctl status is up, but i'm a bit worried about the output:

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

Here is the output for the netstat -tlpn | grep 1521:

tcp6       0      0 :::1521                 :::*                    LISTEN      1298/tnslsnr

Also, the 3 files *.ora files were not added from the start inside $ORACLE_HOME/network/admin/, so i've added them from the 'samples/', but I think most of them are empty/commented out.

I've also tried reenabling firewalld service and starting it, adding a firewall exception for the port, and also adding a firewall exception in GCP, but still cannot make it happen.

Please let me know what else I am missing. Thanks!

user1686 avatar
fr flag
Can you `telnet ::1 1521` **and** `telnet 127.0.0.1 1521` from inside the server? Does a `tcpdump -n -iany port 1521` show any incoming packets whenever you attempt to connect from outside?
Romeo Ninov avatar
in flag
Also `tnsping` (on local machine) can help
Flavian Rotaru avatar
fj flag
```telnet ::1 1521 Trying ::1... Connected to ::1. Escape character is '^]'. ```
Flavian Rotaru avatar
fj flag
```telnet 127.0.0.1 1521 Trying 127.0.0.1... Connected to 127.0.0.1. Escape character is '^]'.```
mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.