TNS-12203 unable to connect to destination

From: Pradeep <agarwalp_at_eeism.com>
Date: 10 Jan 2006 03:39:37 -0800
Message-ID: <1136893177.477723.132160@g43g2000cwa.googlegroups.com>

I get the the above message whenever i try to connect to the database. below is my listener.ora & tnsnames.ora file Oracle 8.0, on Win 2000
listener.ora-> Location C:\orant\NET80\ADMIN\listener.ora

LISTENER=
(DESCRIPTION =

        (ADDRESS=
          (PROTOCOL= TCP)
          (Host= musn0003)
          (Port= 1521)
        )

)

SID_LIST_LISTENER =
(SID_LIST =

    (SID_DESC =
      (SID_NAME = MX2P)     )
  )

tnsnames.ora location-> C:\orant\NET80\ADMIN\listener.ora

MX2P=
(DESCRIPTION =

    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = musn0003)(PORT = 1521))     )
    (CONNECT_DATA =
      (SERVICE_NAME = MX2P.XYZ.com)
    )
   )

I tried the following:

SQL> connect scott/tiger_at_MX2P.XYZ.com
ERROR:
ORA-12154: TNS:could not resolve service name

SQL> connect / as sysdba
ERROR:
ORA-12203: TNS:unable to connect to destination

Please help Received on Tue Jan 10 2006 - 05:39:37 CST