Anyone sophisticated enough to deploy NAC would understand its limitations and, in my opinion, be fully aware that it is not a one-size-fits-all security solution.
Most organisations deploying NAC are doing so in an attempt to gain more control over their clients, rather than just for security. Some companies are even using it as an easier way to update their client software, with no thought to security at all.
Despite this, having some security is better than none. NAC does offer some security benefits and "a lack of completeness" is no excuse for doing nothing at all. Organisations need to decide what is important for them and analyse the tools based on their specific business requirements. More organisations view NAC as a systems management solution than a security solution, but this will change.
Gary Hemminger, Director, Product Marketing, Foundry Networks.