SMC Networks TIGERSWITCH SMC6752AL2 - Manual (Page 191)

VLAN C
ONFIGURATION
3-143
Note: VLAN-tagged frames can pass through VLAN-aware or
VLAN-unaware network interconnection devices, but the VLAN
tags should be stripped off before passing it on to any end-node
host that does not support VLAN tagging.
VLAN Classification – When the switch receives a frame, it classifies the
frame in one of two ways. If the frame is untagged, the switch assigns the
frame to an associated VLAN (based on the default VLAN ID of the
receiving port). But if the frame is tagged, the switch uses the tagged
VLAN ID to identify the port broadcast domain of the frame.
Port Overlapping – Port overlapping can be used to allow access to
commonly shared network resources among different VLAN groups, such
as file servers or printers. Note that if you implement VLANs which do
not overlap, but still need to communicate, you can connect them by
enabled routing on this switch.
Untagged VLANs – Untagged (or static) VLANs are typically used to
reduce broadcast traffic and to increase security. A group of network users
assigned to a VLAN form a broadcast domain that is separate from other
VLANs configured on the switch. Packets are forwarded only between
ports that are designated for the same VLAN. Untagged VLANs can be
used to manually isolate user groups or subnets. However, you should use
IEEE 802.3 tagged VLANs with GVRP whenever possible to fully
automate VLAN registration.
VA
VA: VLAN Aware
VU: VLAN Unaware
VA
tagged frames
VA VU VA
tagged
frames untagged
frames