Windows native operating system authentication for Oracle

While logged into a Windows 2008 server which had an Oracle Database installed, i was trying to get logged in as sysdba using O/S authentication.

I kept getting insufficient priviliges in the error message even as the owner of the oracle software and being in the ora_dba administrator group.

At the time i had been patching their weblogic and fusion middleware tiers and was finishing on the database. I'd completed the task on training environment the day before without issue and this was now their UAT system. I could not find anyone who could tell me the sys password or where i could find it to try to get in through external authentication.

Luckily for me over lunch, my manager who was also onsite remembered hitting the issue before due to a setting in the sqlnet.ora file and after lunch we had a look.

#SQLNET.AUTHENTICATION_SERVICES=(nts)
SQLNET.AUTHENTICATION_SERVICES=(none)
Changing the above around fixed the issue and so i had to go and figure out the why as i wasn't familiar with this setting.

Oracle Documentation Example

Use the parameter SQLNET.AUTHENTICATION_SERVICES to enable one or more authentication services. If authentication has been installed, it is recommended that this parameter be set to either none or to one of the authentication methods.

nts for Windows native operating system authentication

Clear as day, it needs to be set to NTS for windows o/s authentication, i have a feeling i'll remember this setting from now on.