Specifications

Installation and Operation Manual Chapter 1 Introduction
LA-210 Ver. 1.5 Functional Description 1-9
Table 1-2. Ingress Process
Frame Admission Mode Ingress Filtering Mode Bridge Behavior
Admit all frames Enable
Disable
VLAN tagged frames with a VID (or PVID for
untagged/priority tagged frames) that do not include
the bridge port in their VLAN member set, are dropped.
All frames pass.
Admit VLAN tagged
frames
Enable
Disable
VLAN tagged frames with a VID that do not include the
bridge port in their member set are dropped.
Untagged/priority-only tagged frames are dropped.
All VLAN tagged frames pass. Untagged/priority-only
tagged frames are dropped.
Frames that pass this stage are submitted to the forwarding and learning
processes.
Learning Process
The learning process observes the source MAC address (SA) and the VID of the
received frame, and updates the forwarding database with the MAC VID pair and
with the bridge port that the frame was received from. The Forwarding Data Base
(FDB) is also referred to as a MAC table.
Entries in the MAC table can be dynamic (inserted by the learning process) or
static (inserted by configuration). A dynamic entry has an aging time associated
with it.
The LA-210 VLAN-aware bridge is an Independent VLAN Learning (IVL) bridge.
The learning process inserts a new dynamic entry into the MAC table. This entry
consists of a MAC-VID pair and bridge port.
• If the MAC-VID pair already exists for the same port, the aging time is
updated
• If the MAC-VID pair already exists but for a different bridge port (dynamic
entry), the new entry overrides the existing one
• If the MAC-VID pair already exists for a different bridge port (static entry), the
static entry prevails.
Aging Process
The aging process checks the forwarding MAC table periodically. Each dynamic
entry-aging period that has exceeded the configured aging time limit is deleted.
The aging period represents the time passed since the last frame for this entry
entered the bridge. The periodic check of the MAC table (aging time intervals)
results in the actual aging time that can reach up to twice the value that was
configured by the user.