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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 19 Configuring IEEE 802.1Q and Layer 2 Protocol Tunneling Configuring IEEE 802.1Q Tunneling
Configuring an IEEE 802.1Q Tunneling Port
Beginning in privileged EXEC mode, follow these steps to configure a port as an IEEE 802.1Q tunnel
port:
Use the no switchport mode dot1q-tunnel interface configuration command to return the port to the
default state of dynamic desirable. Use the no vlan dot1q tag native global configuration command to
disable tagging of native VLAN packets.
This example shows how to configure an interface as a tunnel port, enable tagging of native VLAN
packets, and verify the configuration. In this configuration, the VLAN ID for the customer connected to
Gigabit Ethernet interface 7 on stack member 1 is VLAN 22.
Switch(config)# interface gigabitethernet1/0/7
Switch(config-if)# switchport access vlan 22
% Access VLAN does not exist. Creating vlan 22
Switch(config-if)# switchport mode dot1q-tunnel
Switch(config-if)# exit
Switch(config)# vlan dot1q tag native
Switch(config)# end
Switch# show dot1q-tunnel interface gigabitethernet1/0/7
Port
-----
Gi1/0/1Port
-----
Switch# show vlan dot1q tag native
dot1q native vlan tagging is enabled
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface interface-id Enter interface configuration mode for the interface to be configured as a
tunnel port. This should be the edge port in the service-provider network
that connects to the customer switch. Valid interfaces include physical
interfaces and port-channel logical interfaces (port channels 1 to 48).
Step 3 switchport access vlan vlan-id Specify the default VLAN, which is used if the interface stops trunking.
This VLAN ID is specific to the particular customer.
Step 4 switchport mode dot1q-tunnel Set the interface as an IEEE 802.1Q tunnel port.
Step 5 exit Return to global configuration mode.
Step 6 vlan dot1q tag native (Optional) Set the switch to enable tagging of native VLAN packets on all
IEEE 802.1Q trunk ports. When not set, and a customer VLAN ID is the
same as the native VLAN, the trunk port does not apply a metro tag, and
packets could be sent to the wrong destination.
Step 7 end Return to privileged EXEC mode.
Step 8 show running-config
show dot1q-tunnel
Display the ports configured for IEEE 802.1Q tunneling.
Display the ports that are in tunnel mode.
Step 9 show vlan dot1q tag native Display IEEE 802.1Q native VLAN tagging status.
Step 10 copy running-config startup-config (Optional) Save your entries in the configuration file.