Hi All.
I was wondering if someone can help me with a problem with oracle DCN - database change notification. I am not a DBA and our DBA's do not seem to have the knowledge. We have run a series of network tests with DCN on a new system - checking netstat -na and tcpdump on the machines to see exactly how the connections are opened. We see this
1. User logs into database on connection port - EG 1521. Connection is on 57100 local port - connectivity initiated Application -> Database
2. User subscribes to DCN for 2 tables
2.1 Subscription added to the database and port 47632 assigned (default DCN port is 47632, but we have seen up to 47638, depending on available ports)
2.2 No additional tcp connections are opened for the notifications
3. When table is updated and notification sent
3.1 Oracle Database initiates the tcp connection with the registered IP;PORT - connectivity Database -> Application
3.2 notification sent by Database and received by application
3.3 we now see new tcp connections on 47632 port
The issue we have is that because the database is hosted offsite our security rules prohibit connections being initiated from database to application.
Is there a way where we can get the Application to open the connection on subscription?
I know the application can specify the port but I cannot find anything to get the connection to be opened by the application before any notifications are sent.
Thanks
Gareth