608 G8264 Application Guide for ENOS 8.4L2 Failover with Other FeaturesL2 Failover works together with static LAGs, Link Aggregation Control Protocol(LACP), and with Spanning Tree Protocol (STP), as described in the next sections.Static LAGsWhen you add a portchannel (static LAG) to a failover trigger, any ports in thatLAG become members of the trigger. You can add up to 64 static LAGs to a failovertrigger, using manual monitoring.LACPLink Aggregation Control Protocol allows the switch to form dynamic LAGs. Youcan use the admin key to add up to 64 LACP LAGs to a failover trigger usingautomatic monitoring. When you add an admin key to a trigger, any LACP LAGwith that admin key becomes a member of the trigger.Spanning Tree ProtocolIf Spanning Tree Protocol (STP) is enabled on the ports in a failover trigger, theswitch monitors the port STP state rather than the link state. A port failure resultswhen STP is not in a Forwarding state (such as Learning, Discarding, or No Link)in all the Spanning Tree Groups (STGs) to which the port belongs. The switchautomatically disables the appropriate control ports.When the switch determines that ports in the trigger are in STP Forwarding state inany one of the STGs it belongs to, then it automatically enables the appropriatecontrol ports. The switch fails back to normal operation.For example, if a monitor port is a member of STG1, STG2, and STG3, a failoverwill be triggered only if the port is not in a forwarding state in all the three STGs.When the port state in any of the three STGs changes to forwarding, then thecontrol port is enabled and normal switch operation is resumed.
