Abstract: A distributed firewall system is used to implement a network firewall with enhanced control over network traffic to allow policy to be implemented on a per-user basis, a per-application basis, a per-user and application basis, and to allow ports to be dynamically opened and closed as needed by the applications. The distributed firewall system may include application identifiers associated with applications running on a network element, one or more firewall agents instantiated on the network element hosting the applications, and a firewall configured to interface with the firewall agents. Communications between the distributed components are secured to allow the firewall to detect if an agent has been compromised, and to allow the firewall agent to determine if the application has been compromised. The distributed firewall system may work in a VPN environment, such as in connection with a VPN server, to implement firewall policy at the point where VPN traffic enters the protected network.