If your server is behind a firewall or there is some personal firewall on
your client PC, and you are running under Windows (and server is on
Windows, too), you may be bumping into port redirection: when client
connects to the TNS listener on Windows, listener sends a redirection
packet that instructs client to connect on different port (and specifies
that port.) Client then attempts to connect to that different port and gets
blocked by firewall. This issue is due the fact that with Winsock 1 it was
not possible to share TCP sockets between different processes. Winsock
2 has this ability, and Oracle 8+ knows how use it, but you need to
set special parameter in registry to enable this feature, and restart both
the listener and the instance. Create the following string value in registry
under HKLM\SOFTWARE\ORACLE: USE_SHARED_SOCKET and set it to
TRUE. If you are running in MTS mode, you may need to specify some
particular ports in init.ora to lock MTS dispatchers to these particular
ports (default is to use any available unprivileged port.) TNSPING succeeds
because it only sends a test packet to the listener, receives a reply and
disconnects, thus it is not affected by port redirection issue. If you use
8.1.7, you have to update to at least 8.1.7.2 as shared sockets feature
was broken in 8.1.7.0 and 8.1.7.1.
hth.
--
Vladimir Zakharychev (bob@dpsp-yes.com) http://www.dpsp-yes.com
Dynamic PSP(tm) - the first true RAD toolkit for Oracle-based internet applications.
All opinions are mine and do not necessarily go in line with those of my employer.
"Guy" <ni4ni_at_hotmail.com> wrote in message news:d2eb532b.0210010037.40d4232f_at_posting.google.com...
> Hello
>
> I have installed a new Database instance on a remote machine.
> Basically it looks fine. I can log in to oracle from within the same
> machine (so the DB is ok).
> When I ping the server from my desktop machine i get a good reply,
> even when I tnsping it I get a reply, so the listener is up too.
> But when I try logging in from my desktop using sqlplus or toad or
> whatever I get an "operation timed out" message.
>
> What can be wrong ??? How come that I can tnsping but cant connect ?
>
> Thanks
>
> Guy Shilo
Received on Tue Oct 01 2002 - 05:45:52 CDT
