GeoLogics Team personnel will investigate the use of current and emerging security and VLAN standards being produced by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee (LMSC) under Project 802. IEEE LMSC working group 802.10 is chartered with producing the Standard for Interoperable LAN/MAN Security (SILS) and IEEE LMSC working group 802.1 is chartered with, among other things, producing an interoperable VLAN standard. The SILS working group has produced a Data Link Layer security standard that provides the capability to cryptographically separate communities of interest (otherwise known as VLANs) that operate simultaneously on the same media at different security levels. The standard allows for tagging (explicitly or implicitly ) each protocol data unit (PDU) with a security label appropriate to the data contained in the PDU, as well as providing a method of tagging each PDU with an identifier for grouping end stations into multicast groups on the LAN. The standard is intended for implementation in end stations, bridges, and bridging routers that implement IEEE LMSC Medium Access Control (MAC) standards, for example, CSMA/CD (a.k.a. Ethernet) and Token Ring, and bridging standards. The standard also operates in conjunction with FDDI networks since the same MAC definition (ISO/IEC IS 10039) is used in the FDDI standard, as well as ATM network products that implement the same MAC interface using AAL5. The GeoLogics Team will study all aspects of these current standardization efforts and their applicability to Navy requirements, and as necessary, will recommend modifications to these proposed standards.