The computer society has not yet agreed on a standard method to measure data security and consequently to date no specific security metric has been defined for routing purposes. This paper used access control, authentication and cryptography to define routing metrics. These metrics are believed to be good, reasonable and practical. Since authentication is regarded as the first line of defense, cryptography is the key tool that ensures secure transmission of data across a network and access control systems help in guaranteeing the availability of services delivered by the information system. Each metric thus demonstrates the level of achievement in preserving the three goals of security.