User guide

Bridge Multiple VLAN support
iMG/RG Software Reference Manual (ADSL Port)
8-38
In the opposite direction, packets arriving from qinterface (connection a) are filtered by the bunbridge module
and only tagged packets having VID = 1 are sent to ip0 interface.
8.4.2 Multiple VLAN support
Bunbridge port is an intermediate layer between the bridge qinterface and the ethernet transport t1. This inter-
mediate layer is used to separate tagged frames received from qinterface based on the VID value:
• It remove the tag header from tagged framed with VID=1 and then forward them to ip0 interface;
• it forward any other tagged frames with VID ≠1 to an additional intermediate port, named ethernet1 (see
example below).
Ethernet1 port looks like an additional system port that receives tagged frames (from the bridge) and forward
them to Ethernet transports modules depending on the VID value. Each Ethernet transport will then remove
the tag header from the frames and will forward such untagged frames to the IP interface attached to it.
Once frames are arrived to the IP layer, routing functions as well as any other functionality that operates at
layer 3/4 can be performed.
FIGURE 8-3 Example of system architecture to support multiple vlan management
vlan 7
vlan 1
qinterface
Bridge Software
bunbridge
VID 4 (tagged)
VID 7 (tagged)
VID 1 (tagged)
VID 4 (tagged)
VID 7 (tagged)
VID 1 (tagged)
VID 4 (tagged)
VID 7 (tagged)
VID 1 (tagged)
VID 4 (tagged)
VID 7 (tagged)
VID 1 (tagged)
t1
ip0
bunbridge
VID 4 (tagged)
vlan_4
ip_4
bunbridge
VID 7 (tagged)
VID 1 (untagged)VID 4 (untagged)VID 7 (untagged)
vlan_7
ip_7
defaulti
default
lan1 lan2 lan3 lan4
ethernet0
ethernet1
vlan 4
cpu
vlan 7
vlan 4
vlan 1