Re: oracle access problems with a linksys router installed

From: Karsten Farrell <kfarrell_at_belgariad.com>
Date: Wed, 13 Nov 2002 16:34:56 GMT
Message-ID: <QavA9.19$IQ.2433353@newssvr21.news.prodigy.com>

Dave Penn wrote:
> I have a similar problem. I've installed a Netgear FVS 318 router and now
> cannot get to the Oracle server either directly through the LAN or via the
> Internet (gives an ORA-12535 tns: operation timed out error), though
> internally the server's JSP applications (with hostname set to "127.0.0.1")
> can access the db just fine.
>
> Oracle server (also JSP application server) is 8i Enterprise Edition running
> on Win2K. Has fixed (reserved) IP address in the router's LAN IP setup.
> Router sends all Internet traffic requests on port 1521 to this fixed IP
> address. Listener is set up at port 1521. Have tried setting up an
> additional listener at 1522 and connecting to it instead, but to no avail.
>
> Clients are also Win2K.
> Appreciate any help. I just want to be able to run another server as a
> development server that can connect to the 8i db when it needs to,
> preferable over the LAN. Would also like to be able to connect using
> SQL*Plus.
>
> Thanks,
> Dave Penn
>
> "Dennis Glorioso" <dglorioso_at_mscamerica.com> wrote in message
> news:98e68896.0211121551.3a5c847a_at_posting.google.com...
>

>>I installed a linksys router on the network to provide internet access
>>to clients. This was replacing a proxy server s/w app. it was also
>>necessary have server internet access ( for Nav Updates) The server
>>has a static IP. After adding a gateway to the Server IP setup (
>>required by Lynksys when using static Ip) my clients can no longer
>>access the Oracle database hosted on that server. Any Idea how to
>>resolve this situation would be apperciated.

>

Here's what happens when you try to connect a Client to the database Server:

Client contacts Listener (Server) on port 1521 (default, or any other you specify in listener.ora).
Listener says "I hear you" and passes control off to a Dispatcher.
Dispatcher allocates a new "random" port and attempts to communicate with Client on this new port. I suspect your router blocks this new port because that's a good thing to do (don't want to open all ports to the world).
Client waits and waits, but you've blocked the Client-Dispatcher "handshake" from getting thru the random port. Finally Client gives up and times out.

If this is what's happening to you, there are several solutions depending on your particular environment. The one I use is to setup a Multi-Threaded Server (MTS) on our Solaris server that communicates over specific, not random, ports which are opened to Net8 only on our firewall. WinNT/2k has to play around with sockets (but our Win2k development database is inside our firewall, so I didn't have to deal with that).

If you have Metalink (requires a support CSI), you can look up Note 125021.1 "Oracle Connectivity with Firewalls". If you don't have Metalink, you can search Google for "firewall oracle port".

If this isn't even remotely related to your problem, forgive my "lecture." :) Received on Wed Nov 13 2002 - 10:34:56 CST