This paper contains a discussion of internet access problem today is very high, this resulted in increased demand for access to a secure network is getting higher. This situation requires the network admin to be more selective in allowing users to access to the network. To these problems is a method to overcome that is by using the method of Network Admission Control (NAC). The application aims to make security systems more reliable and easier, because the system can detect the identity of a personal computer that supports the dynamic vlan. Generally these applications can make a change vlan on cisco Switch by java application using the perl libraries and make the interested users can access and obtain access rights according to existing rules on the network so as to reduce the risk of the illegal user can be dangerous and expense of others. . Keyword: dynamic vlan, Network Admission Control,cisco,librar
