Oracle 10g Exception: ORA-12638 Solution

Issue:

When you create a instance and a database after your install Oracle 10g. You may come across following exception in D:/oracle/product/10.2.0/db_2/BIN/sqlnet.log

***********************************************************************
Fatal NI connect error 12638, connecting to:
(DESCRIPTION=(ADDRESS=(PROTOCOL=BEQ)(PROGRAM=oracle)(ARGV0=oraclencsoft)(ARGS='(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))'))(CONNECT_DATA=(SID=ncsoft)(CID=(PROGRAM=D:/oracle/product/10.2.0/db_2/bin/sqlplus.exe)(HOST=YEXY1)(USER=yexy1))))

  VERSION INFORMATION:
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
Oracle Bequeath NT Protocol Adapter for 32-bit Windows: Version 10.2.0.1.0 - Production

  Time: 07-7月 -2010 13:33:07
  Tracing not turned on.
  Tns error struct:
    ns main err code: 12638
    TNS-12638: 身份證明檢索失敗
    ns secondary err code: 0
    nt main err code: 0
    nt secondary err code: 0
    nt OS err code: 0

Reason:

Oracle DB cannot execute OS autheration.

Solution:

Please go to D:/oracle/product/10.2.0/db_2/NETWORK/ADMIN and try to modify sqlnet.ora as below.

# This file is actually generated by netca. But if customers choose to

# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.

SQLNET.AUTHENTICATION_SERVICES = (NONE)