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how to resolve ORA-12638: Credential retrieval failed

Posted by Pavan DBA on May 19, 2010


Hi Friends, today i faced very nasty situation in establishing network connection with Oracle database.

I created a user as per request from application team and i got response that they are not able to connect. when analyzing i found tnsping is not working.

I started looking at tnsnames.ora and compared that with what is there in server and its same. so as next step i looked at SQLNET.ORA file and added following line to make sure both the machines are in same domain

NAMES.DEFAULT_DOMAIN = klpcph.local

Still nothing worked. Then i tried telnet from client machine and realized that 1521 port is blocked at firewall level.

Once firewall team provided access, tnsping worked but it throwed ORA-12638 : credential retrieval failed error

I found following line in sqlnet.ora file

SQLNET.AUTHENTICATION_SERVICES= (NTS)

Then i modified the above line as below and it started working

SQLNET.AUTHENTICATION_SERVICES= (NONE)

Reason : 

Oracle client attempt to use your current Windows domain credentials to authenticate you with the Oracle server. This could fail for a couple of reasons:

– The Oracle server is not configured to support Windows authentication
– The credentials you use to login to your local machine are not sufficient to allow you to login to the server.

In my case, it was the later. This failed because I was logged on to my local machine using my normal domain credentials rather than my administrator account. 

Posted in Networking with Oracle | Tagged: , | 20 Comments »

 
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