Lacp Modes - Lenovo CN4093 Application Manual

LACP Modes

148
CN4093 Application Guide for N/OS 8.3
To avoid the Actor switch ports (with the same admin key) from aggregating in
another LAG, you can configure a LAG ID. Ports with the same admin key
(although with different LAG IDs) compete to get aggregated in a LAG. The LAG
ID for the LAG is decided based on the first port that is aggregated in the LAG.
Ports with this LAG ID get aggregated and the other ports are placed in
suspended mode. As per the configuration shown in
aggregated first, then the LAG ID of port 38 would be the LAG ID of the LAG. Port
40 would be placed in suspended mode. When in suspended mode, a port
transmits only LACP data units (LACPDUs) and discards all other traffic.
A port may also be placed in suspended mode for the following reasons:
 When LACP is configured on the port but it stops receiving LACPDUs from the
partner switch.
 When the port has a different LAG ID because of the partner switch MAC being
different. For example: when a switch is connected to two partners.
LAG ID can be configured using the following command:
CN 4093(config)# portchannel <65-128> lacp key <adminkey of the LAG>
LACP provides for the controlled addition and removal of physical links for the
link aggregation.
Each port in the CN4093 can have one of the following LACP modes.
off (default)

The user can configure this port in to a regular static LAG.
active

The port is capable of forming a LACP LAG. This port sends LACPDU packets
to partner system ports.
passive

The port is capable of forming a LACP LAG. This port only responds to the
LACPDU packets sent from a LACP active port.
Each active LACP port transmits LACP data units (LACPDUs), while each passive
LACP port listens for LACPDUs. During LACP negotiation, the admin key is
exchanged. The LACP LAG is enabled as long as the information matches at both
ends of the link. If the admin key value changes for a port at either end of the link,
that port's association with the LACP LAG is lost.
If a LACP LAG member port is connected to a port that is in LACP off mode, the
LACP port will not be able to converge and the link goes down.
When the system is initialized, all ports are by default in LACP off mode and are
assigned unique admin keys. To make a group of ports capable of being aggregated,
you assign them all the same admin key. You must set the port's LACP mode to
active to activate LACP negotiation. You can set other port's LACP mode to
passive, to reduce the amount of LACPDU traffic at the initial LAG-forming stage.
Table 16, if port 38 gets