Before revision: A High Assurance Guard (HAG) is a Multilevel security computer device which is used to communicate between different Security Domains , such as NIPRNet to SIPRNet.
After revision: A High Assurance Guard (HAG) is a Multilevel security computer device which is used to communicate between different Security DomainsCNSSI 4009NISTIR 7298 Rev 2NIST SP 800-32 , such as NIPRNet to SIPRNet.