Configuring link fault signaling

By default, both TX and RX LFS are enabled. You can disable either RX or TX LFS globally or on the interface level.

1. From privileged EXEC mode, access global configuration mode.
   

   device# configure terminal

2. Globally change the LFS, if required.
   

   device(config)# link-fault-signaling rx off tx on

   In this example, the global LFS is disabled for the link fault RX and enabled for link fault TX.
3. Access the interface configuration mode for the port that you want to configure.
   

   device(config)# interface Ethernet 0/1

4. Shut down the interface.
   

   device(conf-if-eth-0/1)# shutdown

   The interface must be in the shutdown state before you disable or enable TX LFS.
5. Change the LFS for the interface.
   

   device(conf-if-eth-0/1)# link-fault-signaling rx on tx off 
   

   In this example, the LFS for the interface is enabled for the link fault RX and disabled for the link fault TX. This configuration on the interface overrides the global configuration.
6. Enable the interface.
   

   device(conf-if-eth-0/1)# no shutdown

7. Verify the configuration for the interface.
   

   device(conf-if-eth-0/1)# do show running-config interface ethernet 0/1
   interface Ethernet 0/1
   ...
    link-fault-signaling rx on tx off 
    no shutdown
   !
   

Example

The following example shows the steps in the previous configuration.

device# configure terminal
device(config)# link-fault-signaling rx off tx on
device(config)# interface Ethernet 0/1
device(conf-if-eth-0/1)# shutdown 
device(conf-if-eth-0/1)# link-fault-signaling rx on tx off 
device(conf-if-eth-0/1)# no shutdown