Decoding LACP Port State
It’s frustrating when the output to a show
command gives exactly the information needed, but in a format which is unintelligible. So it is with the Partner Port State field in the NXOS show lacp neighbor interface
command which reports the partner port state as a hexadecimal value. To help with LACP troubleshooting, here’s a quick breakdown of the port states reported on by LACP, and how they might be seen in Junos OS and NXOS.
LACP Port State
The LACP port state (also known as the actor state) field is a single byte, each bit of which is a flag indicating a particular status. In this table, mux
(i.e. a multiplexer) refers to the logical unit which aggregates the links into a single logical transmitter/receiver.
The meaning of each bit is as follows:
Bit | Name | Meaning |
---|---|---|
0 | LACP_Activity | Device intends to transmit periodically in order to find potential members for the aggregate. This is toggled by mode active in the channel-group configuration on the member interfaces.1 = Active, 0 = Passive. |
1 | LACP_Timeout | Length of the LACP timeout. 1 = Short Timeout, 0 = Long Timeout |
2 | Aggregation | Will allow the link to be aggregated. 1 = Continue reading |