Presentation given in Denver on 10/13/95: PROPOSED VLAN SERVICE DEFINITION Paul Frantz, Bay Networks, Inc. Martin McNealis, Cisco Systems, Inc. Tony Moraros, Cisco Systems, Inc. IEEE 802.1 10/12/95 An 802 Virtual Network is an interconnected set of LAN segments providing the 802 VLAN Service described below to the devices attached to those LAN segments. 802 VLAN Service is defined as follows: 1. When a port on the VLAN network receives a packet from an attached device, it maps that packet onto a VLAN based on one or more of the following criteria: - MAC SA - MAC DA (primarily of interest for multicast) - Port Configuration - Ethernet Type, 802 DSAP, SSAP or SNAP header fields - Other packet fields Whether implementations are free to choose which subset of these criteria to support or whether a fixed set of device classes is defined is for further study. 2. The VLAN network retransmits the packet on each segment other than the originating segment which meets one of the following criteria: - Unicast DA: A device whose MAC address matches the unicast DA is known to exist on the segment and the network configuration allows traffic for the VLAN on that segment. TAllows trafficU means that either the MAC DA has been configured as part of the VLAN and there is no segment/port configuration data which explicitly denies either the VLAN or the device from using the segment/port, or that the segment/port is itself configured to always allow traffic for the VLAN. In the case where there is no such segment, the packet is transmitted on all segments where the port/segment configuration allows traffic for the VLAN. - Broadcast DA: The packet is retransmitted on each segment where there is at least one known MAC SAP configured in the VLAN and the port/segment configuration does not deny access either to the particular MAC SAP or to the VLAN, or if there is no such allowed MAC SAP, the segment/port is itself configured to always allow traffic for the VLAN. - Multicast DA: The packet is retransmitted on all segments where the network configuration allows traffic for the VLAN except when the configuration indicates that a subscription protocol (TBD) is in use on the segment, in which case the packet is transmitted only if allowed by the subscription protocol Notes: - The standard shall be suitable for connecting routers to switches over a single physical link, multiplexing the virtual router interfaces over that link. - The Virtual Network allows connection of multiple MAC SAPs with the same MAC address provided the network configuration is such that the set of VLANs to which they and segments on which they are connected belong does not overlap among the various instances of the MAC SAPs.