Here at Interop, there's a lot of focus on security and a lot of that security attention is aimed right at network access control. It's a hot-button topic here. The question plaguing many IT and security managers, though, might be where to get started.After several years of availability but no real steam behind it, businesses are turning their attention to NAC. Big businesses. Small businesses. They're all talking about NAC here at Interop. With all of the news out in the past few years about intrusions, zombie computers, and data loss, NAC technology seems like a smart answer to a lot of security questions.

Network access control is largely about enabling IT managers to take control of who and what devices come onto their networks. When an employee, visitor, or contractor tries to log onto the network, a NAC solution can check to make sure that the machine isn't infected with any malware, that its software is patched and updated, and that antivirus products are running. And if it's a visitor logging on, well, she doesn't need access to the company network, just an Internet connection.

I've been interviewing a lot of vendors about NAC this week. What it's all about… what it can do for a company… what it can't do… and the challenges around deploying it. I've talked with people from Identity Engines, Juniper Networks, LANdesk Software, and Microsoft. There's some interesting things coming up in the area and I'll be reporting on them soon.

But there's one common theme to most, if not all, of these interviews.

How should companies get started with it? How much is not enough? And maybe even worse, how much is too much?

You can set up a NAC solution to check and see if a desktop, laptop, or smartphone has antivirus running and updated software. However, you also could set it up to check for a slew of other things, like configurations and settings. If you go whole-hog on this, the machines coming onto your system will be safe and clean as a whistle. The problem, experts told me, is that very few systems may actually be able to get onto your system.

And what would that do to productivity?

Paul Mayfield, a group program manager at Microsoft, said there are some basic steps to follow when setting up a NAC solution.

First, decide what your policy is going to be. Where are the areas you really need to provide protection for versus areas you're not so worried about? And then start out slowly. Get your feet wet. Don't worry about setting up the system to check for more than just a few things right out of the gate.

And this is key -- go through every desktop, every laptop, and every handheld device or smartphone to make sure they all comply with your new network access regulations. If you don't do this, you might have a big mess on your hands the day you flip the switch. Mayfield advises that managers may want to set it up so people who aren't in compliance at the beginning get a window of time to get their systems into compliance. After a matter of days or a week, they'll be excluded from the network if they aren't up to speed.

"When you're thinking about your policy, it's about bringing your teams together to work through this process," said Mayfield.