This article help us to understand a failure scenario for a LACP aggregate interface due to incorrect link-speed
In QFX5100 the aggregate interface link state is in down state.
ae1 up down
It is observed in the earlier code, aggregate port was able to establish connection with the remote end, even with the difference in link-speed on the aggregate port. However with the new 21 code, it is mandatory to have same link-speed configured at both the end of the ae bundle.
Please refer the below 3 tested scenario
In this scenario, we have configured 2 different link speed on each end of the aggregate interface.
set interfaces ae1 aggregated-ether-options link-speed 10g set interfaces ae1 aggregated-ether-options link-speed 40g labroot@jtac-qfx5100-48s-6q-r2435> show lacp interfaces ae1 Aggregated interface: ae1 LACP state: Role Exp Def Dist Col Syn Aggr Timeout Activity et-0/0/50 Actor No No Yes Yes Yes Yes Fast Active et-0/0/50 Partner No No Yes Yes Yes Yes Fast Active et-1/0/50 Actor No No Yes Yes Yes Yes Fast Active et-1/0/50 Partner No No Yes Yes Yes Yes Fast Active LACP protocol: Receive State Transmit State Mux State et-0/0/50 Current Fast periodic Collecting distributing et-1/0/50 Current Fast periodic Collecting distributing
The aggregate port is observed to be up and running.
With both the side on 21.4R3-S3.4 code. The aggregate interface remains down, due to difference in the link-speed. It is mandatory to have same link-speed configured at both the end of the aggregate link starting from 21 code.
Logs messages pointing to difference on link-speed.
Oct 6 13:29:16 jtac-qfx5100-48s-6q-r2435 /kernel: kernel did not add link ae1, link speeds differ (Child : 40000000000) and (Parent : 10000000000) Oct 6 13:29:16 jtac-qfx5100-48s-6q-r2435 /kernel: bundle ae1.0: link et-0/0/50 not added due to speed mismatch Oct 6 13:29:16 jtac-qfx5100-48s-6q-r2435 /kernel: kernel did not add link ae1, link speeds differ (Child : 40000000000) and (Parent : 10000000000) Oct 6 13:29:16 jtac-qfx5100-48s-6q-r2435 /kernel: bundle ae1.0: link et-1/0/50 not added due to speed mismatch
No Physical interface gets added to the ae1 bundle.
After correcting the link-speed on the aggregate interface ae1, the physical gets attached to the aggregate bundle.
set interfaces ae1 aggregated-ether-options link-speed 40g
^
Check the LACP status.
labroot@jtac-qfx5100-48s-6q-r2435> show lacp interfaces ae1 Oct 06 14:24:55 Aggregated interface: ae1 LACP state: Role Exp Def Dist Col Syn Aggr Timeout Activity et-0/0/50 Actor No No Yes Yes Yes Yes Fast Active et-0/0/50 Partner No No Yes Yes Yes Yes Fast Active et-1/0/50 Actor No No Yes Yes Yes Yes Fast Active et-1/0/50 Partner No No Yes Yes Yes Yes Fast Active LACP protocol: Receive State Transmit State Mux State et-0/0/50 Current Fast periodic Collecting distributing et-1/0/50 Current Fast periodic Collecting distributing
From Junos code 21, the LACP aggregate bundle requires to have identical link speed configured on both the ends of the aggregate interface.