flapping
jargonnetworking
An interface or route that keeps going down and up, down and up - never quite dead, never quite stable.
A flapping link resets protocol adjacencies on every transition, so one bad SFP or loose patch cable can ripple through OSPF and BGP far beyond the port itself. BGP even grew a defense, route-flap damping, because a single flapping route can churn tables across the wider internet.
Also known as: link flap, route flapping