Can't connect to IBM DB2 (SQL30081N)

Question

I want to use ibm_db_django to connect to a DB2-database.

The database runs on a Windows 7 x64 system. I also installed ibm_db and ibm_db_django on the same system. I developed my app on this computer and everything works fine.

Now I wanted to deploy the django-project to a debian 6 x64 system. After some trial I installed the IBM Data Server Client (version 9.5, Fix Pack 10) and added the ODBC-driver for 32-bit. After this I was able to install ibm_db and ibm_db_django. Now I am able to import ibm_db (as long as I am logged in as the db2inst1-user).

The problem is that I cannot connect to my DB2-server:

db2inst1@debian:~$ sqllib/db2profile 
db2inst1@debian:~$ source /home/ai/project/ENV/bin/activate
(ENV)db2inst1@debian:~$ python /home/ai/project/sourcecode/manage.py shell
>>> from django.db import connections
>>> connections['db2'].cursor()
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/home/ai/ENV/lib/python2.6/site-packages/django/db/backends/__init__.py", line 324, in cursor
    cursor = self.make_debug_cursor(self._cursor())
  File "/home/ai/project/ENV/lib/python2.6/site-packages/ibm_db_django/base.py", line 191, in _cursor
    self.connection, cursor = self.databaseWrapper._cursor( None, kwargs )
  File "/home/ai/project/ENV/lib/python2.6/site-packages/ibm_db_django/pybase.py", line 74, in _cursor
    connection = Database.pconnect( **kwargs )
  File "/home/ai/project/ENV/lib/python2.6/site-packages/ibm_db_dbi.py", line 634, in pconnect
    raise _get_exception(inst)
OperationalError: ibm_db_dbi::OperationalError: [IBM][CLI Driver] SQL30081N  Kommunikationsfehler.  Verwendetes Kommunikationsprotokoll:"TCP/IP".  Verwendete Kommunikations-API: "SOCKETS".  Position, an der der Fehler erkannt wurde: "192.168.23.123".  \xc3\x9cbertragungsfunktion, die den Fehler festgestellt hat: "connect".  Protokollspezifische(r) Fehlercode(s): "110", "*", "*".  SQLSTATE=08001 SQLCODE=-30081

I defined the database-connection like this:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'database_name',
        'USER': 'username',
        'PASSWORD': 'password',
        'HOST': '',
        'PORT': '',
    },
    'db2': {
        'ENGINE'     : 'ibm_db_django',
        'NAME'       : 'SAMPLE',
        'USER'       : 'username',
        'PASSWORD'   : 'password',
        'HOST'       : '192.168.23.123',
        'PORT'       : '50000',
        'PCONNECT'   :  True,      #Optional property, by default it is false
    }
}

I only changed the HOST, compared to the running version on my Windows 7 development machine. Pinging the IP does work and the connection should be stable (the debian-machine is a virtual machine connected to the same router as the physical windows-7-machine).

Does anyone have a clue?