Specifications

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System Management Software Configuration Guide for Cisco IE 2000U and Connected Grid Switches
Chapter 17 Configuring Ethernet OAM, CFM, and E-LMI
Enabling Ethernet Loopback
To stop an active loopback session on an interface or to stop all active loopback sessions, enter the
ethernet loopback stop {interface-id | all} privileged EXEC command. To remove the Ethernet facility
loopback configuration, enter the no ethernet loopback interface configuration command.
EXAMPLE
This example shows how to configure an Ethernet loopback to swap the MAC source and destination
addresses. to never time out, and to start the loopback process. You must confirm the command before
loopback starts.
Switch(config)# interface gigabitethernet 0/1
Switch(config-if)# ethernet loopback facility mac-address swap timeout none supported
Switch(config-if)# end
Switch# ethernet loopback start gigabitethernet 0/1
This is an intrusive loopback.
Therefore, while you test Ethernet connectivity,
you will be unable to pass traffic across that link.
Proceed with Local Loopback? [confirm]
This is the output from the show ethernet loopback privileged EXEC command for the previous
configuration:
Switch# show ethernet loopback
=====================================
Loopback Session 0 : Interface Gi0/1
Direction : facility
Type : port
Status : configured
MAC Mode : swap
Time out : none.
Step 4
end Return to privileged EXEC mode.
Step 5
ethernet loopback {start interface-id | stop
{interface-id | all}
Turn on (start) Ethernet loopback on an interface, or
turn off (stop) Ethernet loopback on an interface or
on all interfaces.
Note When you enter the command to start
loopback, you receive a message that this is
an intrusive loopback on the port or VLAN
and that you will not be able to pass packets.
You must confirm the command.
Step 6
show ethernet loopback [interface-id]
show interface interface-id, show interface
status, show log
Verify the configuration for the switch or for an
interface.
Verify that loopback is running (has been started) on
an interface.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration
file.
Command Purpose