Users Guide

788 VLANs
DVLAN CE interfaces must be configured for tagging (dot1q-tunnel mode)
for double tags to be observed on frames egressing the service provider (SP)
interface. The DVLAN SP interface should be configured to accept tagged
frames for the DVLAN or outer VLAN (trunk or general mode). Ensure that
the native (access mode) VLAN on the customer edge (CE) port is set to the
DVLAN ID. MAC address learning on DVLAN enabled ports occurs on the
DVLAN CE port's native VLAN.
If it is desirable to restrict propagation of spanning tree topology changes
from CE interfaces into the service provider network, enable spanning-tree
tcnguard on the CE interfaces. Optionally, use the spanning-tree guard root
on CE ports to eliminate the possibility that a CE interface becomes a root
port. Be aware that root guard may cause spanning-tree to stop forwarding if a
superior BPDU is received on the interface.
Perform the following steps to configure an interface as a CE interface. The
DVLAN VLAN must also be configured on an interface with tagging enabled
(trunk or general mode), and the native VLAN must be set to the DVLAN
VLAN identifier.. That interface will act as the SP interface. It is advisable to
restrict the allowed VLAN on the SP interface to the DVLAN VLAN only.
Command Purpose
configure Enter global configuration mode.
vlan 100 Create the DVLAN (outer) VLAN.
exit Exit VLAN configuration mode
switchport dot1q
ethertype vman
Define the VMAN EtherType for use on the CE port.
interface interface-id Enter interface configuration mode for the specified CE
interface. The interface-id variable includes the interface
type and number, for example tengigabitethernet 1/0/3.
A range of interfaces can be specified using the interface
range command. For example, interface range
tengigabitethernet 1/0/8-12 configures interfaces 8, 9, 10,
11, and 12.
switchport mode dot1q-
tunnel
Configure the interface as a CE tunnel port.
switchport access vlan
100
Configure the DVLAN VLAN