Customer reported that their BFD and ISIS protocol flaps on this particular interface between two QFX's
Jan 9 16:39:11.389 QFX bfdd[8619]: BFDD_TRAP_SHOP_STATE_UP: local discriminator: 41, new state: up, interface: ae2.0, peer addr: 162.151.89.30
Jan 9 20:15:13.191 QFX bfdd[8619]: BFDD_STATE_UP_TO_DOWN: BFD Session 162.151.89.30 (IFL 545) state Up -> Down LD/RD(41/23) Up time:03:36:02 Local diag: CtlExpire Remote diag: None Reason: Detect Timer Expiry.
Jan 9 20:15:13.191 QFX bfdd[8619]: BFDD_TRAP_SHOP_STATE_DOWN: local discriminator: 41, new state: down, interface: ae2.0, peer addr: 162.151.89.30
Jan 9 20:15:13.193 QFX rpd[8612]: RPD_ISIS_ADJDOWN: IS-IS lost L1 adjacency to rur02.a4atlanta.ga.atlanta on ae2.0, reason: BFD Session Down
Jan 9 20:15:13.193 QFX rpd[8612]: RPD_ISIS_ADJDOWN: IS-IS lost L2 adjacency to rur02.a4atlanta.ga.atlanta on ae2.0, reason: BFD Session Down
Jan 9 20:15:18.314 QFX bfdd[8619]: BFDD_TRAP_SHOP_STATE_UP: local discriminator: 41, new state: up, interface: ae2.0, peer addr: 162.151.89.30
Customer removed BFD configuration (as per their standard they do not have BFD on these QFX devices).
Once removed the BFD configurations, even other protocol stayed up and stable.