Re: Ports used by Oracle

From: <Philippe.Michel_at_Thales-IS.com>
Date: 26 Apr 2001 06:33:43 GMT
Message-ID: <9c8fg7$pfr$1@news.syseca.fr>

In article <P_yF6.2074$9e7.7549_at_monolith.news.easynet.net>, Jason Bowsher <jason.bowsher_at_remoteapps.com> wrote:
>We are currently using an application which is told to connect to an Oracle
>database on port 1521 via a Oracles JDBC thin driver.
>
>I have noticed that when this application queries an Oracle 8.1.6 database
>on an x86 LINUX RH6.2 server a snoop shows that communication takes place at
>port 1521 on the Oracle server. As illustraded below:
> [...]
>However when the same host and application query an Oracle 8.1.6 database on
>a SPARC Solaris8 server a snoop shows that communication takes place on
>various high numbered ports. As illustrated below;
>[...]
>Can anyone tell me if there is some Oracle configuration parameter which
>would result in the server not using port 1521. I believe that the
>listeners on the oracle server are configured to use port 1521.

The database on the Solaris server probably uses mts and dispatchers. In this case, there is an initial connection to the listener on port 1521 but most of the communication takes place on the ports assigned to the dispatchers.

By default, the dispatchers use random ports, but you may set them in the init.ora file ; something like :

mts_max_dispatchers = 4
mts_dispatchers = "(address=(protocol=tcp)(host=whatever)(port=15210))(dispatchers=1)"
mts_dispatchers = "(address=(protocol=tcp)(host=whatever)(port=15211))(dispatchers=1)"
mts_dispatchers = "(address=(protocol=tcp)(host=whatever)(port=15212))(dispatchers=1)"
mts_dispatchers = "(address=(protocol=tcp)(host=whatever)(port=15213))(dispatchers=1)"

local_listener = "(address=(protocol=tcp)(host=whatever)(port=1521))"

Note that if the server runs NT, it uses random ports even with dedicated servers, so if using selected ports is important (to connect through a filtering router or a firewall for instance), you must use mts. Received on Thu Apr 26 2001 - 01:33:43 CDT