Re: Sqlplus not work with VPN, but tnsping work

aaa wrote:
> I tried to access our ORACLE server through VPN. The problem I have
is
> "sqlplus" not work, but tnsping work. Network engineer told me he
did open port
> 1521 for me.
>
> if I use ORACLE "tnsping" on PC side, it will response back. Server
side have
> message "15-DEC-2004 20:36:38 * ping * 0" on listener.ora file.
>
>
> If I use "sqlplus" on PC, there is message pop-up:
> ORA-12535: TNS: Operation time out
>
> there is NO message on ORACLE server side listener.ora file.
>
>
> Anyone know why?
>
> Thanks.

Not from what you've written so far. On which operating system is Oracle running? If it's any form of Windows (NT,2000,XP) port forwarding is likely your culprit.

Let us say, for a moment, you are running Oracle on Windows. Port 1521 is open, and it receives the initial request as expected. Windows, without your knowledge or consent, will take that request from port 1521 and redirect it to a port of its own choosing, without giving you the slightest hint of its actions. Your connection is now on port 1732, for instance, and since this is no longer 1521, and since 1732 is not likely to be open by your network admin, you get the ORA-12535 error and the connection times out.

Why does tnsping work? The tnsping utility does not establish a connection to the database, it merely pings the port listed in the tnsnames.ora file for the given connect destriptor and determines if it can make contact. No port forwarding is involved, as it's merely a ping.

An acceptable route around this dilemma is to configure Connection Manager outside of your firewall. It will negotiate the connection to the Oracle database, and remain on the configured port so communioation is not lost. It will not matter that Windows has redirected your request from port 1521 to 1888 (or some other wild choice of port) as all traffic between the clients and the database passes through Connection Manager. One port open in your firewall, and no undesirable effects of Windows port forwarding.

Of course, all of that may be completely off-base, as you may not be running Oracle on Windows.

When you let us know the operating system in use for the Oracle database server a better, and possibly more complete, answer can be given.

David Fitzjarrell Received on Wed Dec 15 2004 - 21:15:24 CST