link-fault-signal
Configures RX and TX Link Fault Signaling (LFS) detection globally or on an interface port.
Syntax
link-fault-signal
rx
{
off
|
on
}
tx
{
off
|
on
Command Default
Both TX and RX LFS are enabled.
Parameters
- rx
- Configure RX LFS detection.
- off
- Disables LFS.
- on
- Enables LFS.
- tx
- Configure TX LFS detection.
Modes
Global and interface configuration modes
Usage Guidelines
Use the
no form of the command to reset RX and TX LFS to their default settings of enabled.
The interface must be in the shutdown state before you disable or enable TX LFS.
All SLX devices support LFS detection for
interface types of 10G, 40G, 100G, and 40G breakout ports. It detects local and
remote faults.
LFS is not supported in 1G mode.
When the device detects a local fault, it returns a remote fault to the link partner. When the device detects a remote fault, it returns an idle state.
A port's physical link detection is independent of LFS detection. When either of these link fault signals is detected, the following behaviors occur:
- The link is declared as DOWN and the management
interface should display Protocol Down on the SLX-OS CLI.
- The physical link is not bought down in both of the previous cases. The peer side based on its implementation might display that the link is UP when the device displays that the link is DOWN due to a fault detection.
- The transmit (TX) packets, if any, are dropped at the MAC layer. The receive (RX) packets, if any, are dropped in the software.
- The detected signal is reported as a RASTRACE
message. The same information is reported on the management interface as a
RASLOG. The same behavior occurs when the signal is cleared.
You can enable or disable LFS globally and on the interface level for both RX and TX directions:
- If the LFS is enabled for RX, the normal local and remote fault detection and processing described previously occur. If it is disabled for RX, local and remote fault detection are ignored.
- If the LFS is enabled for TX and a local fault occurs, a remote fault (pause frame) is generated to the remote side. If it is disabled for TX, the remote fault is not generated.
The interface configuration overrides the global configuration.
Examples
The following example shows the global and interface configuration of LFS. In this example, the global LFS is disabled for the link fault RX and enabled for link fault TX. The LFS for the interface is enabled for the link fault RX and disabled for the link fault TX, overriding the global 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
