Cisco 1941W Configuration Manual page 42

Ethernet Data Plane Loopback
or
encapsulation dot1q vlan-id second-dot1q inner vlan-id
ethernet loopback permit external
Step 5
end
Step 6
DETAILED STEPS
Command
Step 1
enable
Example:
Router>enable
Step 2
configure terminal
Example:
Router#configure terminal
Step 3
interface gigabitethernet
slot/port.sub-port
Example:
Router(config)#interface
gigabitethernet 0/2.1101
Step 4
encapsulation dot1q vlan-id
or
encapsulation dot1q vlan-id
second-dot1q inner vlan-id
Example:
Router(config-subif)#encapsulation
dot1q 100
or
Router(config-subif)#encapsulation
dot1q 100 second-dot1q 1101
Step 5
ethernet loopback permit external
Example:
Router(config-subif)#ethernet
loopback permit external
Step 6
end
Example:
Router(config-subif)#end
Cisco 3900 Series, Cisco 2900 Series, and Cisco 1900 Series Integrated Services Routers Generation 2 Software Configuration Guide
34
Chapter Configuring Ethernet CFM and Y.1731 Performance Monitoring on Layer 3 Interfaces
Purpose
Enables the privileged EXEC mode.
Enter your password when prompted.
Enters the global configuration mode.
Specifies the subinterface and enters the subinterface
configuration mode.
Defines the encapsulation format as IEEE 802.1Q
(dot1q), and specifies the VLAN identifier.
For double tagging, use the second-dot1q keyword and
the inner vlan-id argument to specify the VLAN tag.
Configures Ethernet external loopback on the
subinterface.
Exits the subinterface configuration mode.