Lenovo ThinkSystem NE2552E, Application Manual

Page: 442 / 574

442
NE2552E Application Guide for ENOS 8.4
L2 Failover with Other Features
L2 Failover works together with Link Aggregation Control Protocol (LACP) and
with Spanning Tree Protocol (STP), as described in the next sections.
LACP
Link Aggregation Control Protocol allows the switch to form dynamic LAGs. You
can use the admin key to add up to two LACP LAGs to a failover trigger using
automatic monitoring. When you add an admin key to a trigger, any LACP LAG
with that admin key becomes a member of the trigger.
Note:
If you change the LACP system priority on an LACP aggregation, the
failover trigger goes down.
Spanning Tree Protocol
If Spanning Tree Protocol (STP) is enabled on the ports in a failover trigger, the
switch monitors the port STP state rather than the link state. A port failure results
when STP is not in a
Forwarding
state (such as
Learning
,
Discarding
or
No
Link
). The switch automatically disables the appropriate internal ports, based on
the VLAN monitor.
When the switch determines that ports in the trigger are in STP
Forwarding
state,
then it automatically enables the appropriate internal ports, based on the VLAN
monitor. The switch fails back to normal operation .