Security is a very common concern in It infrastructures, while its deployement is usually subject to a lot of discussions, maybe because it’s alway’s difficult to buy an off-the-shelf “security” box. You need to know what to secure first, based on your own security policies.

Once the policies have been defined, you can then implement something. Of course, this can be a difficult exercise.
Fixon-It will help you understanding security in your own context, and further can implement it for you.