If you want to communicate with secure SNMP packets, you will need to
set up SNMP security parameters for your system.  If so, copy these
files into your /etc directory and edit them according to the
instructions at the beginning of each file.  Unfortunately, knowledge
of SNMP Security is a great help here.  This will get better in the
future -- automated tools should do this work.

For simple SNMP-V1 communication, these files must be present in /etc,
but there is no need to edit.
