IEEE 802.1Q VLANs
145
Tagging or untagging VLAN frames
ATTENTION
VLAN-tagged frames can pass through VLAN-aware or VLAN-unaware network
interconnection devices, but the VLAN tags should be stripped off before passing
the frame on to any end-node host that does not support VLAN tagging.
The following concepts apply to VLAN configuration:
•
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. If you implement VLANs that do not
overlap, but still need to communicate, you can connect them by using
an external router.
•
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,
use IEEE 802.3 tagged VLANs with GVRP whenever possible to fully
automate VLAN registration.
SMB
Using the Nortel Business Ethernet Switch 50 Series
NN47924-301
01.01
Standard
1.00
October 2006
Copyright © 2006, Nortel Networks
Nortel Networks Confidential
.
Summary of Contents for BES50FE-12T PWR
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