IEEE 802.3ad Link Aggregation troubleshooting

Use the entstat command to troubleshoot IEEE 802.3ad Link Aggregation.

If you are having trouble with your IEEE 802.3ad Link Aggregation, use the following command to verify the mode of operation of the Link Aggregation:

entstat -d device

where device is the Link Aggregation device.

This will also make a best-effort determination of the status of the progress of LACP based on the LACPDUs received from the switch. The following status values are possible:

Inactive: LACP has not been initiated. This is the status when a Link Aggregation has not yet been configured, either because it has not yet been assigned an IP address or because its interface has been detached.
Negotiating: LACP is in progress, but the switch has not yet aggregated the adapters. If the Link Aggregation remains on this status for longer than one minute, verify that the switch is correctly configured. For instance, you should verify that LACP is enabled on the ports.
Aggregated: LACP has succeeded and the switch has aggregated the adapters together.
Failed: LACP has failed. Some possible causes are that the adapters in the aggregation are set to different line speeds or duplex modes or that they are plugged into different switches. Verify the adapters' configuration.
In addition, some switches allow only contiguous ports to be aggregated and may have a limitation on the number of adapters that can be aggregated. Consult the switch documentation to determine any limitations that the switch may have, then verify the switch configuration.

Note: The Link Aggregation status is a diagnostic value and does not affect the AIX® side of the configuration. This status value was derived using a best-effort attempt. To debug any aggregation problems, it is best to verify the switch's configuration.

The following IEEE 802.3ad Link Aggregation statistics represent the status of the LACP on each port of the aggregation.

They are shown for both the Actor (the IEEE 802.3ad Link Aggregation) and for the Partner (the switch port).

System Priority: priority value for this system
System: value that uniquely identifies this system
Operational Key: value that denotes which ports may be
       aggregated together
Port Priority: priority value for this port
Port: unique value that identifies this port in the aggregation
State:
       LACP activity: Active or Passive - whether to initiate
              sending LACPDUs always, or only in response to
              another LACPDU: the IEEE 802.3ad Link Aggregation
              will always operate in Active mode
       LACP timeout: Long or Short - time to wait before
              sending LACPDUs: the IEEE 802.3ad Link Aggregation
              will always use the long timeout
       Aggregation: Individual or Aggregatable - whether this
              port can form an aggregation with other ports, or
              if it can only form an aggregation with itself:
              the port in a one-adapter IEEE 802.3ad Link Aggregation
              will be marked as Individual, or Aggregatable
              if there are more than one ports
       Synchronization: IN_SYNC or OUT_OF_SYNC - whether the
              aggregation has determined it has reached
              synchronization with the partner
       Collecting: Enabled or Disabled - whether the IEEE 802.3ad
              Link Aggregation is collecting (receiving) packets
       Distributing: Enabled or Disabled - whether the IEEE 802.3ad
              Link Aggregation is distributing (sending) packets
       Defaulted: True or False - whether the IEEE 802.3ad
              Link Aggregation is using default values for
              the partner's information
       Expired: True or False - whether the IEEE 802.3ad
              Link Aggregation is operated in expired mode

The following statistics are shown on both a port-by-port and aggregate basis:

Received LACPDUs: LACPDU packets received
Transmitted LACPDUs: LACPDU packets sent out
Received marker PDUs: marker PDUs received
Transmitted marker PDUs: marker PDUs sent:
       this version of the protocol does not implement the
       marker protocol, so this statistic will always be zero
Received marker response PDUs: marker PDUs received
Transmitted marker response PDUs: marker response PDUs sent:
       this version of the protocol does not implement the
       marker protocol, so this statistic will always be zero
Received unknown PDUs: PDUs received of unknown type
Received illegal PDUs: PDUs received of known type, but which
       were malformed, of unexpected length, or unknown subtype