Nawaz
If you want reports of who logged in and of what changes were made then I suggest that the best way to do this is with aaa accounting. aaa accounting exec should produce an accounting record every time anyone logs in and starts an exec session. aaa accounting commands 15 will produce accounting records for every privilege level command that is entered which will allow you to see all changes that were made.
The accounting records are sent to the TACACS/ACS server which can produce reports of who logged in and what changes were made.
HTH
Rick
HTH
Rick
