Below are a few of the common causes of errors that might be found and their suggested solutions.
. /home/db2inst1/sqllib/db2profile
Note: In the above example, notice that the '.' is followed by a single space character.
Note: On Unix and Linux platforms the DB2 user must have a db2profile at $HOME/sqllib/db2profile
On Unix platforms, you can use ifconfig to determine the subnet mask.