THOMSON R7.4, Configuration Manual

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E-DOC-CTC-20080229-0001 v1.0
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4| Ethernet Bridge and VLANs
4.8 Extra Tagging (Stacked VLANs)
Introduction
The CLI commands explained in this section belong to the command group
:eth bridge xtratag
.
What is VLAN stacking?
VLAN stacking means that a frame contains two VLAN tags:
An inner VID , also referred to as the local VID.
An outer VID , also referred to as the WAN-side VID.
General configuration of the bridge
Before using the unknown VID policy feature, make following preparations:
VLAN awareness of the bridge : the bridge must be able to interpret the VLAN tags of received frames.
Hence, the bridge must be VLAN aware.
By default, the bridge is non-VLAN aware. To make the bridge VLAN aware, execute following command:
Extra tagging mode
Each bridge port can be configured with an extra tagging mode .
By default, the extra tagging mode is set to none. To change the mode, execute the command
:eth bridge ifconfig
and specify the value of the parameter
xtratagging
.
=>:eth bridge config vlan=enabled
For more information on VLAN awareness, see “4.3 VLAN Awareness” on page 16