The db2level command will help you determine the version and service level
(build level and FixPak number) of your DB2 instance. To determine if your DB2
instance is at the latest service level, compare your db2level output to the build
level and FixPak information on the FixPak download pages at the DB2 UDB
support web site.

A typical result of running the db2level command on a Windows system would be:

db2level

Output
DB21085I Instance "DB2" uses "32" bits and DB2 code release "SQL08020" with level identifier "03010106". Informational tokens are "DB2 v8.1.7.664", "s040914", "WR21342", and FixPak "7". Product is installed at "C:\IBM\SQLLIB".

The combination of the four informational tokens uniquely identify the precise
service level of your DB2 instance. This information is essntial when contacting
IBM support for assistance. In particular, the second informational token shows the
date that the product was built. In the above example, s040914 indicates a build
date of September 14th, 2004.

For JDBC or SQLJ application, if you are using the Universal Driver for SQLJ and
JDBC, you can determine the level of the driver by running the db2jcc utility:

db2jcc -version

Output
IBM DB2 JDBC Universal Driver Architecture 2.3.63

On Windows, this command is in the sqllib\bin directory.
On UNIX/Linux, this command is in the sqllib/bin directory.
DB2 server