MicroBFD prevents AE bundle to come up
Lets say an AE bundle goes down due to its member link going down. If MicroBFD is configured, the AE interface fails to come up though it shows in CD state under show lacp interfaces.
This is because when a member link goes down, the BFD state moves to NOT_ENABLED and Junos sends "down" to the kernel, causing AE to go down, which is not expected.
This can be verified under lacpd.log file
lacpd_bfd_state_change: xe-0/0/0:0: BFD state change from UP to NOT_ENABLED
lacpd_bfd_ifd_pointchange:xe-0/0/0:0: BFD state change to kernel as DOWN.
In an ideal scenario, BFD down should not be published to kernel and the logs should look like this
lacpd_bfd_ifd_pointchange:xe-0/0/0:0: BFD state change update to kernel as UP, as BFD is not enabled
As workaround, deactivate/reactivate the MicroBFD configuration will bring the AE interface up.
for eg:
deactivate interfaces ae1 aggregated-ether-options bfd-liveness-detection
commit
activate interfaces ae11 aggregated-ether-options bfd-liveness-detection
This issue has been reported under the PR1912709 https://prsearch.juniper.net/problemreport/PR1912709 and fixed in later releases.