A method may include receiving a digital certificate through a secure connection from a network access server, the secure connection passing through a network address translation device, validating the digital certificate with a policy management system, and establishing a secure tunnel between the network access server and the policy management system when the digital certificate is validated. Also, receiving, through the secure tunnel and from the network access server, a remote authentication dial-in user service access request having a network access server internet protocol address, validating the network access server with the network access server internet protocol address by the policy management system, and allowing a remote authentication dial-in user service traffic when the internet protocol address of the network access server is validated and closing the secure tunnel when the validating the network access server fails.