SOLVED: Re: DNS and SQL*Net Issue

From: mkb <>
Date: Thu, 18 Feb 2010 13:35:06 -0800 (PST)
Message-ID: <>


On Tue, Jan 26, 2010 at 9:15 AM, mkb <> wrote:

>Thanks for the information. What's curious is that the remote site is not using an LDAP server at all in there enclave. But reading the above link, it could be that the SRV record for the newly built server is not in the DNS. Perhaps this could be causing the extra delay? We're only listening on 1521 TCPS so we'd only ever see _ldaps._tcp._oid, right?

I really don't know the answer to that last question.

What I saw in our lab environment didn't match what I saw in production.

The lab worked fine without the LDAPS record, but was required in the production environment.

I could not account for the difference.

Jared Still

So we finally figured out what was happening. We were able to configure a local DNS server and do some testing. In our environment, when we pointed the Oracle server to our DNS. We didn't notice any performance issues. We had tcpdump running on the DNS server and we could see requests to the DNS server but no performance issues at our site.

Our goal was to disable the database server querying DNS even if we had a valid entry in resolv.conf as this was causing the performance issues at the remote site. All we did was add an ldap.ora file on the database server in $TNS_ADMIN but we configured our ldap.ora file as follows:

DIRECTORY_SERVER_TYPE = OID Re-starting the listener we now note that the database server makes no requests to DNS which resolved the performance issue that the remote site was experiencing.

Appreciate the help! Thanks


Received on Thu Feb 18 2010 - 15:35:06 CST

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