Link Fault Signaling for 10Gbps Ethernet devices

Link Fault Signaling (LFS) is a physical layer protocol that enables communication on a link between two 10 Gbps Ethernet devices. When configured on a Ruckus 10 Gbps Ethernet port, the port can detect and report fault conditions on transmit and receive ports.

When LFS is enabled on an interface, the following Syslog messages are generated when the link goes up or down, or when the TX or RX fiber is removed from one or both sides of the link that has LFS enabled.

Interface ethernet 1/1/1, state down - link down
Interface ethernet 1/1/1, state up

When a link fault occurs, the Link and Activity LEDs turn OFF.

The Link and Activity LEDs turn ON when there is traffic traversing the link after the fiber is installed.

On Brocade FastIron devices, RX LFS is always enabled by default and cannot be disabled. The [no] link-fault-signal command only applies to enabling or disabling TX LFS.