Timeline for JDBC oracle listener random port
Current License: CC BY-SA 4.0
10 events
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| Mar 8, 2022 at 12:39 | comment | added | pmdba | The Oracle Community thread linked by Ed below also goes into great detail on this: community.oracle.com/tech/developers/discussion/4486985/… | |
| Mar 8, 2022 at 12:24 | comment | added | pmdba | From the client's perspective (and the firewall) the connection still goes through the SCAN IP and is never broken. The original connection is "handed off" to a different server process (dedicated server, shared server, etc.) on the server side without affecting the TCP connection, so the port number doesn't change. See here: oracle.com/webfolder/technetwork/tutorials/…, docs.oracle.com/en/database/oracle/oracle-database/21/netag/… | |
| Mar 8, 2022 at 8:27 | comment | added | miracle173 | I am not sure if I understand your comment. What does "the client connection is handed off (not reconnected)" mean?. If your clients connects to a scan listener of a RAC, the scan listener tells the client to which local listener it should connect. This connection to both listeners is written to their log files. The destination port of the connection to the local listener is the port defined for the local listener and not the port of the scan listener. Of course in configuration both ports are 1521. There are no problems with "traditional" firewalls if you configure the correct rules. | |
| Mar 7, 2022 at 14:37 | comment | added | pmdba | The key here is that the destination port is always fixed and known (default 1521, but could be other), and the client port is always random. The destination port is generally the same across all services, so that modern security/firewall rules can be supported: the client connection is handed off (not reconnected) from one service to another, but the destination port remains the same. Oracle used to force a change in ports, but they dropped that behavior a long time ago because it was incompatible with host and network firewall protections. | |
| Mar 7, 2022 at 11:57 | comment | added | miracle173 | +1 This is basically correct, but if one has a RAC or shared servers configure then the listener asks the client to open a new connection to the database server on a different port than 1521 | |
| Jul 20, 2021 at 12:48 | history | edited | pmdba | CC BY-SA 4.0 |
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| Jul 20, 2021 at 12:41 | history | edited | pmdba | CC BY-SA 4.0 |
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| Jul 20, 2021 at 12:33 | history | edited | pmdba | CC BY-SA 4.0 |
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| Jul 20, 2021 at 11:23 | history | migrated | from stackoverflow.com (revisions) | ||
| Jul 19, 2021 at 10:44 | history | answered | pmdba | CC BY-SA 4.0 |