Link Fault Propagation; Interaction With Interfaces Violation Recovery - Alcatel-Lucent OmniSwitch 9900 Series Network Configuration Manual

Configuring Ethernet Ports

Link Fault Propagation

The Link Fault Propagation (LFP) feature provides a mechanism to propagate a local interface failure into
another local interface. In many scenarios, a set of ports provide connectivity to the network. If all these
ports go down, the connectivity to the network is lost. However, the remote end remains unaware of this
loss of connectivity and continues to send traffic that is unable to reach the network. To solve this
problem, LFP does the following:
•
Monitors a group of interfaces (configured as source ports).
•
If all the source ports in the group go down, LFP waits a configured amount of time then shuts down
another set of interfaces (configured as destination ports) that are associated with the same group.
•
When any one of the source ports comes back up, all of the destination ports are brought back up and
network connectivity is restored.
The LFP source and destination ports can be physical or link aggregation ports. If the destination port is a
link aggregation port the shutdown consists of shutting down all members of the link aggregation group
(physically down). However, the link aggregation group remains administratively enabled.

Interaction With Interfaces Violation Recovery

•
The clear violation
violation condition still exists.
•
An admin down followed by an admin up will clear the LFP violation and mark the interfaces as up
even if the violation condition still exists.
•
When the destination port is a link aggregate, the shutdown action does not shutdown the link
aggregation. Instead, all the ports that are members of the link aggregation at the time of the violation
are shutdown.
•
A link aggregate port remains in a violation state even if the port leaves the link aggregate.
•
If a port that is not a member of a link aggregate at the time a violation occurred is added to a link
aggregate, the switch will not shut down the port.
•
SNMP traps cannot be configured for LFP. The interface violation recovery mechanism will be
responsible for sending traps when a port is shutdown or recovered by LFP.
•
If the wait-to-restore (WTR) timer is configured on the source ports of a LFP group with link
monitoring enabled, the state of the destination ports of the group will be determined by the link state
of the ports after the WTR timer has expired.
See "Interfaces Violation Recovery" on page 1-15
OmniSwitch AOS Release 8 Network Configuration Guide
command will clear the LFP violations and mark the interfaces as up even if the
for information of learning port violations.
December 2017
Link Fault Propagation
page 1-24