Enterasys Networks 6000 - Manual (Page 90)

Managing the Module 2-71
The Device View
Ports on 802.1Q switches are assigned membership in a VLAN by associating a VLAN ID
with each port on the switch. The VLAN ID is combined with the port’s identification
(e.g., module X port X) to form the Port VLAN ID (PVID).
When 802.1Q is implemented for a SmartSwitch 6000 or Matrix E7 that has an
HSIM-A6DP installed, each LEC will be represented as an individual port which can be
easily assigned membership in a VLAN.
Once VLANs have been configured and activated, all frames with unknown destination
addresses (including broadcast, unknown multicast, and unknown unicast frames) will be
contained within the VLAN of their origin. The switch’s Filtering Database tracks the
associations between MAC addresses, VLAN eligibilities, and port numbers, and is used
to make forwarding decisions for frames. All VLANs share a single Spanning Tree.
Ingress List Operation
A port’s ingress list specifies the VLAN with which received frames will be associated.
The switch’s Filtering Database tracks the associations between VLAN eligibilities, MAC
addresses, and port numbers.
Untagged frames received by an 802.1Q switch port are classified according to the VLAN
membership of the port that receives the frame.
Tagged frames received by an 802.1Q switch port are classified according to the VLAN
indicated in their tag header. A port may receive a tagged frame that specifies a VLAN
other than the one assigned to the port.
Egress List Operation
Each port’s egress list specifies which VLANs are associated with the port, and specifies
what type of frame (tagged and/or untagged) to transmit for each particular VLAN on a
port. This information may be statically defined by the user, or dynamically learned and
maintained by the switch’s Filtering Database.
NOTE
When 802.1Q mode is initially activated on a device, all ports are associated with the
Default VLAN (VLAN ID 1). If a VLAN ID has not been assigned to a particular port on
an 802.1Q switch, any frames received from that port will be classified as belonging to the
Default VLAN.
NOTE
For SmartSwitch 6000 or Matrix E7 firmware versions 4.00.08 and above, the number of
LECs supported by the HSIM-A6DP in 802.1Q mode is limited to 32.