Foundry Networks FESX - Page 287

Configuring Virtual LANs (VLANs)
December 2005 © Foundry Networks, Inc. 11 - 57
Figure 11.22 Dual-mode VLAN port example
To enable the dual-mode feature on port 2/11 in Figure 11.22:
FastIron SuperX Router(config)# vlan 20
FastIron SuperX Router(config-vlan-20)# tagged e 2/11
FastIron SuperX Router(config-vlan-20)# tagged e 2/9
FastIron SuperX Router(config-vlan-20)# int e 2/11
FastIron SuperX Router(config-if-e1000-2/11)# dual-mode
FastIron SuperX Router(config-if-e1000-2/11)# exit
Syntax: [no] dual-mode
You can configure a dual-mode port to transmit traffic for a specified VLAN (other than the DEFAULT-VLAN) as
untagged, while transmitting traffic for other VLANs as tagged. Figure 11.23 illustrates this enhancement.
Figure 11.23 Specifying a default VLAN ID for a dual-mode port
In Figure 11.23, tagged port 2/11 is a dual-mode port belonging to VLANs 10 and 20. The default VLAN assigned
to this dual-mode port is 10. This means that the port transmits tagged traffic on VLAN 20 (and all other VLANs to
which the port belongs) and transmits untagged traffic on VLAN 10.
Hub
Port 2/11
Tagged, VLAN 20
dual-mode
Port 2/9
Tagged, VLAN 20
Port 2/10
Untagged
Untagged
Traffic
VLAN 20
Traffic
Untagged
Traffic
VLAN 20
Traffic
Foundry Device
VLAN 10
Untagged
Traffic
Port 2/9
Tagged, VLAN 20
Port 2/10
Untagged, VLAN 10
VLAN 20
Tagged
Traffic
Hub
Dual-mode Port 2/11
Default VLAN ID 10
Tagged, VLAN 20
VLAN 10
Untagged
Traffic
VLAN 20
Tagged
Traffic
Foundry Device