A method and apparatus for analyzing the perimeter security of communications networks. More particularly, information is identified which defines a particular communications network, e.g., an intranet, and identifying the connected hosts thereto. Utilizing such information, a determination is made with respect to identifying the routes that define the network. Utilizing the routing information, the connectivity of the hosts within the network, e.g., an intranet, is probed to ascertain the integrity of the network and thereby identifying potential security risks across the perimeter defense of the network.