Re: Sqlplus not work with VPN, but tnsping work

Ed Stevens wrote:
[snip]

>
>
> David,
>
> Maybe I missed something, but I don't think it has anything to do with
> Windows. Your basic description of the switch from the 'listening'
> port of 1521 to the 'connection' port of xyz is correct, but it is an
> Oracle issue, not a Windows issue.

Ed,

it's more a Windows issue, since on *nix Oracle uses shared sockets by default, however on Windows using shared sockets is something you have to configure (by setting USE_SHARED_SOCKETS in the registry and restart both the listener and the instance).

And to be precise, it's not a Oracle or windows issue but a TCP/IP thingy: A client creates a communication socket and requests a connection on e.g. port 1521. The listener creates a communication socket with a port assigned by the tcp/ip stack and answers the client's request on this socket.

Whith shared sockets, the listener (after talking to the instance and checking if the database is willing to talk to the client) the listener hands over the socket to the instance.

The default behaviour on Windows however is that the instance creates a new communication socket, tells the listener on what port it will graciously accept a client connection which the listener in turn will tell the client who has to create a *new* connection. At this point the firewall kicks in and denies the connection to the port the instance is now waiting in vain for the client to connect...

And for the historians: IIRC the use of shared sockets is available since NT4 SP3, with a broken implementation in Oracle somewhere around 8i R2

HTH Holger Received on Thu Dec 16 2004 - 08:43:32 CST